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Sample records for anterior corpus callosum

  1. Anterior commissure versus corpus callosum: A quantitative comparison across mammals.

    Science.gov (United States)

    Ashwell, Ken W S

    2016-04-01

    Mammals rely on two major pathways to transfer information between the two hemispheres of the brain: the anterior commissure and the corpus callosum. Metatheria and monotremes rely exclusively on the anterior commissure for interhemispheric transfer between the isocortices and olfactory allocortices of each side, whereas Eutheria use a combination of the anterior commissure and an additional pathway exclusive to Eutheria, the corpus callosum. Midline cross-sectional area of the anterior commissure and corpus callosum were measured in a range of mammals from all three infraclasses and plotted against brain volume to determine how midline anterior commissure area and its size relative to the corpus callosum vary with brain size and taxon. In Metatheria, the square root of anterior commissure area rises in almost direct proportion with the cube root of brain volume (i.e. the ratio of the two is relatively constant), whereas among Eutheria the ratio of the square root of anterior commissure area to the cube root of brain volume declines slightly with increasing brain size. The total of isocortical and olfactory allocortical commissure area rises more rapidly with increasing brain volume among Eutheria than among Metatheria. This means that the midline isocortical and olfactory allocortical commissural area of metatherians with large brains (about 70 ml) is only about 50% of that among eutherians with similarly sized brains. On the other hand, isocortical and olfactory allocortical commissural area is similar in Metatheria and Eutheria at brain volumes around 1 ml. Among the Eutheria, some groups make less use of the anterior commissure pathway than do others: soricomorphs, rodents and cetaceans have smaller anterior commissures for their brain size than do afrosoricids, erinaceomorphs and proboscideans. The findings suggest that use of the anterior commissural route for isocortical commissural connections may have placed limitations on interhemispheric transfer of

  2. Reduced fractional anisotropy in the anterior corpus callosum is associated with reduced speech fluency in persistent developmental stuttering.

    Science.gov (United States)

    Civier, Oren; Kronfeld-Duenias, Vered; Amir, Ofer; Ezrati-Vinacour, Ruth; Ben-Shachar, Michal

    2015-04-01

    Developmental stuttering is a speech disorder that severely limits one's ability to communicate. White matter anomalies were reported in stuttering, but their functional significance is unclear. We analyzed the relation between white matter properties and speech fluency in adults who stutter (AWS). We used diffusion tensor imaging with tract-based spatial statistics, and examined group differences as well as correlations with behavioral fluency measures. We detected a region in the anterior corpus callosum with significantly lower fractional anisotropy in AWS relative to controls. Within the AWS group, reduced anisotropy in that region is associated with reduced fluency. A statistically significant interaction was found between group and age in two additional regions: the left Rolandic operculum and the left posterior corpus callosum. Our findings suggest that anterior callosal anomaly in stuttering may represent a maladaptive reduction in interhemispheric inhibition, possibly leading to a disadvantageous recruitment of right frontal cortex in speech production.

  3. Quantitative assessment of corpus callosum morphology in periventricular nodular heterotopia.

    Science.gov (United States)

    Pardoe, Heath R; Mandelstam, Simone A; Hiess, Rebecca Kucharsky; Kuzniecky, Ruben I; Jackson, Graeme D

    2015-01-01

    We investigated systematic differences in corpus callosum morphology in periventricular nodular heterotopia (PVNH). Differences in corpus callosum mid-sagittal area and subregional area changes were measured using an automated software-based method. Heterotopic gray matter deposits were automatically labeled and compared with corpus callosum changes. The spatial pattern of corpus callosum changes were interpreted in the context of the characteristic anterior-posterior development of the corpus callosum in healthy individuals. Individuals with periventricular nodular heterotopia were imaged at the Melbourne Brain Center or as part of the multi-site Epilepsy Phenome Genome project. Whole brain T1 weighted MRI was acquired in cases (n=48) and controls (n=663). The corpus callosum was segmented on the mid-sagittal plane using the software "yuki". Heterotopic gray matter and intracranial brain volume was measured using Freesurfer. Differences in corpus callosum area and subregional areas were assessed, as well as the relationship between corpus callosum area and heterotopic GM volume. The anterior-posterior distribution of corpus callosum changes and heterotopic GM nodules were quantified using a novel metric and compared with each other. Corpus callosum area was reduced by 14% in PVNH (p=1.59×10(-9)). The magnitude of the effect was least in the genu (7% reduction) and greatest in the isthmus and splenium (26% reduction). Individuals with higher heterotopic GM volume had a smaller corpus callosum. Heterotopic GM volume was highest in posterior brain regions, however there was no linear relationship between the anterior-posterior position of corpus callosum changes and PVNH nodules. Reduced corpus callosum area is strongly associated with PVNH, and is probably associated with abnormal brain development in this neurological disorder. The primarily posterior corpus callosum changes may inform our understanding of the etiology of PVNH. Our results suggest that

  4. Dysgenesis of the corpus callosum

    Energy Technology Data Exchange (ETDEWEB)

    Kendall, B.E.

    1983-08-01

    The embryology of the corpus callosum is briefly reviewed in relation to dysgenesis and associated malformations. The morphology, etiology, clinical and radiological features of such malformations are discussed and illustrated.

  5. Hyperlexia and ambient echolalia in a case of cerebral infarction of the left anterior cingulate cortex and corpus callosum.

    Science.gov (United States)

    Suzuki, Tadashi; Itoh, Shouichi; Hayashi, Mototaka; Kouno, Masako; Takeda, Katsuhiko

    2009-10-01

    We report the case of a 69-year-old woman with cerebral infarction in the left anterior cingulate cortex and corpus callosum. She showed hyperlexia, which was a distinctive reading phenomenon, as well as ambient echolalia. Clinical features also included complex disorders such as visual groping, compulsive manipulation of tools, and callosal disconnection syndrome. She read words written on the cover of a book and repeated words emanating from unrelated conversations around her or from hospital announcements. The combination of these two features due to a focal lesion has never been reported previously. The supplementary motor area may control the execution of established subroutines according to external and internal inputs. Hyperlexia as well as the compulsive manipulation of tools could be interpreted as faulty inhibition of preexisting essentially intact motor subroutines by damage to the anterior cingulate cortex reciprocally interconnected with the supplementary motor area.

  6. Hypnotizability and Corpus Callosum Morphology

    OpenAIRE

    Horton, James Edward

    1999-01-01

    Hypnotizability and Corpus Callosum Morphology By James E. Horton Committee Chair: Helen J. Crawford, Ph.D. Department of Psychology (Abstract) In general, highly hypnotizable individuals ("highs") have exhibited greater abilities to focus attention and inhibit pain than low hypnotizable individuals ("lows"). Furthermore, highs appear to have faster neural processing than lows. The present study investigated differences between lows and highs in morphological volume of s...

  7. EphB1 and EphB2 intracellular domains regulate the formation of the corpus callosum and anterior commissure.

    Science.gov (United States)

    Robichaux, Michael A; Chenaux, George; Ho, Hsin-Yi Henry; Soskis, Michael J; Greenberg, Michael E; Henkemeyer, Mark; Cowan, Christopher W

    2016-04-01

    The two cortical hemispheres of the mammalian forebrain are interconnected by major white matter tracts, including the corpus callosum (CC) and the posterior branch of the anterior commissure (ACp), that bridge the telencephalic midline. We show here that the intracellular signaling domains of the EphB1 and EphB2 receptors are critical for formation of both the ACp and CC. We observe partial and complete agenesis of the corpus callosum, as well as highly penetrant ACp misprojection phenotypes in truncated EphB1/2 mice that lack intracellular signaling domains. Consistent with the roles for these receptors in formation of the CC and ACp, we detect expression of these receptors in multiple brain regions associated with the formation of these forebrain structures. Taken together, our findings suggest that a combination of forward and reverse EphB1/2 receptor-mediated signaling contribute to ACp and CC axon guidance.

  8. Lower fractional anisotropy at the anterior body of the normal-appearing corpus callosum in multiple sclerosis versus symptomatic carotid occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Lou, Xin; Ma, Lin; Cai, Youquan [PLA General Hospital, Department of Radiology, Beijing (China); Jiang, Weijian; Ma, Ning [Capital University of Medical Sciences, Department of Interventional Neuroradiology, Beijing Tiantan Hospital, Beijing (China); Huang, Dehui [PLA General Hospital, Department of Neurology, Beijing (China); Wong, Edward Hochung [Prince of Wales Hospital, Division of Neurology, Department of Medicine and Therapeutics, Hong Kong (China)

    2009-09-15

    Not uncommonly, differentiating multiple sclerosis (MS) from ischemic cerebral vascular disease is difficult based on conventional magnetic resonance imaging (MRI). We aim to determine whether preferential occult injury in the normal-appearing corpus callosum (NACC) is more severe in patients with MS than symptomatic carotid occlusion by comparing fractional anisotropy (FA) from diffusion tensor imaging (DTI). Eighteen patients (eight men, ten women; mean age, 38.6 years) with MS and 32 patients (24 men, eight women; mean age, 64.0 years) with symptomatic unilateral internal carotid occlusion were included. DTI (1.5 T) were performed at corpus callosum which were normal-appearing on fluid-attenuated inversion recovery MRI. Mean FA was obtained from the genu, anterior body, posterior body, and splenium of NACC. Independent-sample t test statistical analysis was performed. The FA values in various regions of NACC were lower in the MS patients than symptomatic carotid occlusion patients, which was statistically different at the anterior body (0.67{+-}0.12 vs 0.74{+-}0.06, P=0.009), but not at genu, posterior body, and splenium (0.63{+-}0.09 vs 0.67{+-}0.07, P=0.13; 0.68{+-}0.09 vs 0.73{+-}0.05, P=0.07; 0.72{+-}0.09 vs 0.76{+-}0.05, P=0.13). MS patients have lower FA in the anterior body of NACC compared to patients with symptomatic carotid occlusion. It suggests that DTI has potential ability to differentiate these two conditions due to the more severe preferential occult injury at the anterior body of NACC in MS. (orig.)

  9. A MRI quantitative study of corpus callosum in normal adults

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective: To investigate the possible age- and sex-related differences in the various dimensions of corpus callosum among Chinese normal adults. Methods: Magnetic resonance images of 286 healthy adults, including 127 males and 159 females, and ranging in age from 20 to 81 years, were investigated. They were classified into 5 age groups (20-29, 30-9, 40-49, 50-59, and 60-81 years old). Corresponding to the age group sequence above, the male/female ratio of each group respectively was: 25/26, 26/33, 33/50, 32/36, and 11/14. The following dimensions of corpus callosum were systematically measured on the midsagittal T1-weighted images: frontal to occipital pole (represented as line segment AB), total longitudinal dimension of the corpus callosum (CD), the maximum height (EF), the widths of the genu (CX), anterior one third (GH), central region (EZ), posterior one third (MN) and splenium (YD). After that, the obtained data was analyzed statistically. Results: (1) The total longitudinal dimension, maximum height, widths of the genu, central region and splenium were proved to be larger in females. But the widths of the anterior one third and posterior one third were similar in-between. In spite of that, a conspicuous sex-related difference was not found. (2) The total longitudinal dimension and the maximum height of the corpus callosum remained stable in all age subgroups. Yet the widths of the genu, anterior one third, central region, posterior one third and splenium had a tendency of decreasing gradually with aging. Statistical difference was seen in the anterior one third, central region, posterior one third (P<0.05). Conclusion: There is no sex-related difference in all dimensions of corpus callosum. But, with aging, a significant difference is found in the widths of the anterior one third, central region and posterior one third.

  10. Corpus Callosum Area in Children and Adults with Autism

    Science.gov (United States)

    Prigge, Molly B. D.; Lange, Nicholas; Bigler, Erin D.; Merkley, Tricia L.; Neeley, E. Shannon; Abildskov, Tracy J.; Froehlich, Alyson L.; Nielsen, Jared A.; Cooperrider, Jason R.; Cariello, Annahir N.; Ravichandran, Caitlin; Alexander, Andrew L.; Lainhart, Janet E.

    2013-01-01

    Despite repeated findings of abnormal corpus callosum structure in autism, the developmental trajectories of corpus callosum growth in the disorder have not yet been reported. In this study, we examined corpus callosum size from a developmental perspective across a 30-year age range in a large cross-sectional sample of individuals with autism…

  11. Sexual dimorphism of the human corpus callosum: Digital morphometric study

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    Spasojević Goran

    2006-01-01

    Full Text Available Background/Aim. Changes in the morphology and the size of the corpus callosum, are related to various pathological conditions. An analysis of these changes requires data about sexual dimorphism of the corpus callosum, which we tried to obtain in our study. We also investigated the method of digital morphometry and compared the obtained results with the results of other authors obtained by magnetic resonance imaging or by planimetry. Methods. A morphological research included 34 human brains (cadavers of both sexes − 19 female and 15 male aged 26−72 years. By digital morphometry using an AutoCAD software we performed measurements in the corpus callosum: the length (L, width in the half of its length (WW’, length of its cortical margin (LCM, area and perimeter of the anterior and posterior callosal segments, as well as the area and perimeter of the corpus callosum section area. The investigated parameters were analyzed and compared between the females and males. Results. There was not a statistically significant difference between the males and females in the investigated parameters of the corpus callosum (t test; p > 0.05, including the mean values of the two most important parameters, the surface of its midsagittal section area (males 654.11 mm2; females 677.40 mm2 and of its perimeter (males 19.61 cm; females 19.72 cm. The results obtained by digital morphometry were in the range of the results of other authors obtained by magnetic resonance and by planimetry. However, the value of Pearson coefficient of linear correlation between the section surface area and perimeter of the corpus callosum in the males was highly significant (rxy = 0.6943, p < 0.01, while in the females this value was statistically insignificant. Conclusion. Digital morphometry is accurate method in encephalometric investigations. Our results suggest that the problem of sexual dimorphism of the corpus callosum is very complex, because the identical variables (section

  12. On Automating and Standardising Corpus Callosum Analysis in Brain MRI

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Skoglund, Karl

    2005-01-01

    Corpus callosum analysis is influenced by many factors. The effort in controlling these has previously been incomplete and scattered. This paper sketches a complete pipeline for automated corpus callosum analysis from magnetic resonance images, with focus on measurement standardisation....... The presented pipeline deals with i) estimation of the mid-sagittal plane, ii) localisation and registration of the corpus callosum, iii) parameterisation and representation of its contour, and iv) means of standardising the traditional reference area measurements....

  13. Agenesis of the corpus callosum and autism: a comprehensive comparison

    OpenAIRE

    Paul, Lynn K.; Corsello, Christina; Kennedy, Daniel P.; Adolphs, Ralph

    2014-01-01

    The corpus callosum, with its ∼200 million axons, remains enigmatic in its contribution to cognition and behaviour. Agenesis of the corpus callosum is a congenital condition in which the corpus callosum fails to develop; such individuals exhibit localized deficits in non-literal language comprehension, humour, theory of mind and social reasoning. These findings together with parent reports suggest that behavioural and cognitive impairments in subjects with callosal agenesis may overlap with t...

  14. Automated measurement of the human corpus callosum using MRI

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    Timothy J Herron

    2012-09-01

    Full Text Available The corpus callosum includes the majority of fibers that connect the two cortical hemispheres. Studies of cross-sectional callosal morphometry and area have revealed developmental, gender, and hemispheric differences in healthy populations and callosal deficits associated with neurodegenerative disease and brain injury. However, accurate quantification of the callosum using magnetic resonance imaging is complicated by intersubject variability in callosal size, shape, and location and often requires manual outlining of the callosum in order to achieve adequate performance. Here we describe an objective, fully automated protocol that utilizes voxel-based image to quantify the area and thickness both of the entire callosum and of different callosal compartments. We verify the method’s accuracy, reliability, robustness and multisite consistency and make comparisons with manual measurements using public brain-image databases. An analysis of age-related changes in the callosum showed increases in length and reductions in thickness and area with age. A comparison of older subjects with and without mild dementia revealed that reductions in anterior callosal area independently predicted poorer cognitive performance after factoring out Mini-Mental Status Examination scores and normalized whole brain volume. Open-source software implementing the algorithm is available at www.nitrc.org/projects/c8c8.

  15. Morphometric changes of the corpus callosum in congenital blindness

    DEFF Research Database (Denmark)

    Tomaiuolo, Francesco; Campana, Serena; Collins, D Louis

    2014-01-01

    We examined the effects of visual deprivation at birth on the development of the corpus callosum in a large group of congenitally blind individuals. We acquired high-resolution T1-weighted MRI scans in 28 congenitally blind and 28 normal sighted subjects matched for age and gender....... There was no overall group effect of visual deprivation on the total surface area of the corpus callosum. However, subdividing the corpus callosum into five subdivisions revealed significant regional changes in its three most posterior parts. Compared to the sighted controls, congenitally blind individuals showed a 12......% reduction in the splenium, and a 20% increase in the isthmus and the posterior part of the body. A shape analysis further revealed that the bending angle of the corpus callosum was more convex in congenitally blind compared to the sighted control subjects. The observed morphometric changes in the corpus...

  16. Cavernous Angioma of the Corpus Callosum Presenting with Acute Psychosis

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    Giacomo Pavesi

    2014-01-01

    Full Text Available Psychiatric symptoms may occasionally be related to anatomic alterations of brain structures. Particularly, corpus callosum lesions seem to play a role in the change of patients’ behavior. We present a case of a sudden psychotic attack presumably due to a hemorrhagic cavernous angioma of the corpus callosum, which was surgically removed with complete resolution of symptoms. Although a developmental defect like agenesis or lipoma is present in the majority of these cases, a growing lesion of the corpus callosum can rarely be the primary cause. Since it is potentially possible to cure these patients, clinicians should be aware of this association.

  17. Delusional Disorder in a Patient with Corpus Callosum Agenesis

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    Saha, Rashmita; Doval, Nimisha

    2016-01-01

    Agenesis of corpus callosum is rare and associated neuropsychiatric abnormalities reported are epilepsy, Asperger’s syndrome, learning problems, depression, schizophrenia, conduct disorder and conversion symptoms. Schizophrenia is the most common psychiatric disorder reported among corpus callosum agenesis. We report a rare case of delusional disorder with corpus callosum agenesis and seizure disorder. The patient presented with delusions of persecution towards younger brother and mother, disturbed sleep and reduced appetite. She had a history of seizure disorder of ten years duration, which was controlled with carbamazepine and levetiracetam. Neurological examination was normal. On MRI, corpus callosum agenesis was detected. She was put on an atypical antipsychotic quetiapine to which her psychiatric symptoms responded completely. PMID:28208982

  18. Hereditary spastic paraplegia with a thin corpus callosum

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    Somasundaram, Sivaraman; Kesavadas, Chandrasekharan [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Imaging Sciences and Interventional Radiology, Trivandrum (India); Raghavendra, Seetharam; Singh, Atampreet; Nair, Muraleedharan [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Neurology, Trivandrum (India)

    2007-05-15

    We report a 15-year-old boy with autosomal recessive complicated hereditary spastic paraplegia with a thin corpus callosum (HSP-TCC). The involvement of the corpus callosum was characteristic with the genu and body predominantly affected with relative sparing of the splenium. HSP-TCC is being increasingly recognized over a wider geographical area than earlier believed. We now report a case of HSP-TCC from the Indian subcontinent. (orig.)

  19. Clinical significance of the corpus callosum in cerebral palsy

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    Lee, Eun Ja; Kim, Ji Chang [The Catholic University of Korea, Seoul (Korea, Republic of); Kim, Jong Chul [School of Medicine, Chungnam National University, Taejon (Korea, Republic of); And Others

    2000-10-01

    To evaluate, using magnetic resonance (MR) imaging, the clinal significance of the corpus callosum by measuring the size of various portions of the corpus callosum in children with cerebral palsy, and in paired controls. Fifty-two children (30 boys and 22 girls aged between six and 96 (median, 19) months) in whom cerebral palsy was clinically diagnosed underwent MR imaging. There were 23 term patients and 29 preterm, and the control group was selected by age and sex matching. Clinal subtypes of cerebral palsy were classified as hemiplegia (n=14), spastic diplegia (n=22), or spastic quadriplegia (n=16), and according to the severity of motor palsy, the condition was also classified as mild (n=26), moderate (n=13), or severe (n=13). In addition to the length and height of the corpus callosum, the thickness of its genu, body, transitional zone and splenium, as seen on midsagittal T1-weighted MR images, were also measured. Differences in the measured values of the two groups were statistically analysed and differences in the size of the corpus callosum according to the clinical severity and subtypes of cerebral palsy, and gestational age, were also assessed. Except for height, the measured values of the corpus callosum in patients with cerebral palsy were significantly less than those of the control group (p less than 0.05). Its size decreased according to the severity of motor palsy. Compared with term patients, the corpus callosum in preterm patients was considerably smaller (p less than 0.05). There was statistically significant correlation between the severity of motor palsy and the size of the corpus callosum. Quantitative evaluation of the corpus callosum might be a good indicator of neurologic prognosis, and a sensitive marker for assessing the extent of brain injury.

  20. Facial emotion recognition in agenesis of the corpus callosum

    OpenAIRE

    Bridgman, Matthew W.; Brown, Warren S.; Spezio, Michael L.; Leonard, Matthew K.; Adolphs, Ralph; Paul, Lynn K.

    2014-01-01

    Background: Impaired social functioning is a common symptom of individuals with developmental disruptions in callosal connectivity. Among these developmental conditions, agenesis of the corpus callosum provides the most extreme and clearly identifiable example of callosal disconnection. To date, deficits in nonliteral language comprehension, humor, theory of mind, and social reasoning have been documented in agenesis of the corpus callosum. Here, we examined a basic social ability as yet not ...

  1. Corpus callosum atrophy is associated with mental slowing and executive deficits in subjects with age-related white matter hyperintensities: the LADIS Study

    DEFF Research Database (Denmark)

    Jokinen, Hanna; Ryberg, Charlotte; Kalska, Hely

    2007-01-01

    processing--namely, trail making A and Stroop test parts I and II. Anterior, but not posterior, corpus callosum atrophy was associated with deficits of attention and executive functions as reflected by the symbol digit modalities and digit cancellation tests, as well as by the subtraction scores in the trail...... making and Stroop tests. Furthermore, semantic verbal fluency was related to the total corpus callosum area and the isthmus subregion. CONCLUSIONS: Corpus callosum atrophy seems to contribute to cognitive decline independently of age, education, coexisting WMH and stroke. Anterior corpus callosum atrophy...... of the total corpus callosum area and its subregions with cognitive performance were analysed using multiple linear regression, controlling for volume of WMH and other confounding factors. RESULTS: Atrophy of the total corpus callosum area was associated with poor performance in tests assessing speed of mental...

  2. Corpus callosum atrophy is associated with mental slowing and executive deficits in subjects with age-related white matter hyperintensities. The LADIS study

    DEFF Research Database (Denmark)

    Jokinen, Hanne; Ryberg, Charlotte; Stegmann, Mikkel Bille

    2007-01-01

    processing--namely, trail making A and Stroop test parts I and II. Anterior, but not posterior, corpus callosum atrophy was associated with deficits of attention and executive functions as reflected by the symbol digit modalities and digit cancellation tests, as well as by the subtraction scores in the trail...... making and Stroop tests. Furthermore, semantic verbal fluency was related to the total corpus callosum area and the isthmus subregion. CONCLUSIONS: Corpus callosum atrophy seems to contribute to cognitive decline independently of age, education, coexisting WMH and stroke. Anterior corpus callosum atrophy...... of the total corpus callosum area and its subregions with cognitive performance were analysed using multiple linear regression, controlling for volume of WMH and other confounding factors. RESULTS: Atrophy of the total corpus callosum area was associated with poor performance in tests assessing speed of mental...

  3. Neuronal fiber composition of the corpus callosum within some odontocetes.

    Science.gov (United States)

    Keogh, Mandy J; Ridgway, Sam H

    2008-07-01

    Odontocetes (toothed whales) evolved from terrestrial mammals approximately 55 million years ago and have since remained on a unique evolutionary trajectory. This study used formalin-fixed tissue and light microscopy to quantify the size and number of fibers along the corpus callosum of the bottlenose dolphin (n = 8). Two other species, the Amazon River dolphin (n = 1) and the killer whale (n = 1), were included for comparison. A large amount of variation in the shape and area of the corpus callosum was observed. The odontocete corpus callosum is a heterogeneous structure with variation in fiber size and density along the length of the corpus callosum in all specimens examined. Using the species with the largest sample size, the bottlenose dolphin, comparisons by sex and age (sexually mature verses immature) were made for the area of the corpus callosum, five subregions, and fiber densities. Although no sex differences were detected, age appeared to affect the size, shape, and fiber composition of the bottlenose dolphin corpus callosum.

  4. Interleukin-6, age, and corpus callosum integrity.

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    Brianne M Bettcher

    Full Text Available The contribution of inflammation to deleterious aging outcomes is increasingly recognized; however, little is known about the complex relationship between interleukin-6 (IL-6 and brain structure, or how this association might change with increasing age. We examined the association between IL-6, white matter integrity, and cognition in 151 community dwelling older adults, and tested whether age moderated these associations. Blood levels of IL-6 and vascular risk (e.g., homocysteine, as well as health history information, were collected. Processing speed assessments were administered to assess cognitive functioning, and we employed tract-based spatial statistics to examine whole brain white matter and regions of interest. Given the association between inflammation, vascular risk, and corpus callosum (CC integrity, fractional anisotropy (FA of the genu, body, and splenium represented our primary dependent variables. Whole brain analysis revealed an inverse association between IL-6 and CC fractional anisotropy. Subsequent ROI linear regression and ridge regression analyses indicated that the magnitude of this effect increased with age; thus, older individuals with higher IL-6 levels displayed lower white matter integrity. Finally, higher IL-6 levels were related to worse processing speed; this association was moderated by age, and was not fully accounted for by CC volume. This study highlights that at older ages, the association between higher IL-6 levels and lower white matter integrity is more pronounced; furthermore, it underscores the important, albeit burgeoning role of inflammatory processes in cognitive aging trajectories.

  5. Infarction of the entire corpus callosum as a complication in subarachnoid hemorrhage: A case report

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    Satoru Takahashi, M.D.

    2017-03-01

    Full Text Available The corpus callosum is the major commissural pathway connecting the cerebral hemispheres. This pathway receives its blood supply from anterior communicating artery, pericallosal artery, and posterior pericallosal artery. However, in some cases, the entire corpus callosum is supplied by median callosal artery; thus, occlusion of this artery can lead to infarction of the entire corpus callosum. Few reports have described this type of infarction, and no reports after subarachnoid hemorrhage (SAH exist. Here, we report on a 42-year-old female who was diagnosed with SAH after two aneurysms were discovered in bifurcation of left anterior cerebral artery (A1-A2. After successful clipping was performed, the patient was alert and had no neurological deficits; moreover, the computed tomography images that were acquired after the operation showed no evidence of infarction. Nine days after admittance to the hospital, drowsiness and weakness of the left limbs with brain swelling appeared and decompressive hemi-craniectomy was performed. Diagnostic cerebral angiography revealed vasospasms in both anterior and middle cerebral arteries, thus fasudil hydrochloride was administered intra-arterially. While blood flow in all arteries improved, diffusion-weighted magnetic resonance imaging detected infarction along the entire length of the corpus callosum and in the medial region of the right frontal lobe. We believe this infarction was due to secondary ischemia of median callosal artery. This case reminded us of the anatomical variation wherein median callosal artery is the sole blood supply line for the corpus callosum and demonstrated that infarction of the entire corpus callosum is possible.

  6. Angular analysis of corpus callosum in 18 patients with frontonasal dysplasia

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    Giffoni Silvyo David Araújo

    2004-01-01

    Full Text Available Considering the rarity of the frontonasal dysplasia (FD and the few reports about it in a large casuistry using magnetic resonance image (MRI, we describe the results of the angular analysis of the corpus callosum of 18 individuals with FD (7 male, 11 female, using an easily-reproductive method. Group I had 12 individuals with isolated form and Group II had 6 individuals with FD syndromic with unknown etiology. The results are presented in set. Comparing with the control group, patients with FD presented alpha angle increase and beta and gamma angles reduction (p<0.05. Alpha and gamma angles express the relationship between the anterior portion of corpus callosum and the floor of 4th ventricle. Considering the embryonary development, these findings would occur secondarily to failure during the development of nasal capsula. Thus, angular anomaly in corpus callosum would be a usual finding, and not fortuitous in patients with FD.

  7. Agenesis of corpus callosum and emotional information processing in schizophrenia

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    Emmanuel eStip

    2012-02-01

    Full Text Available Corpus callosum (CC is essential in providing the integration of information related to perception and action within a subcortico-cortical network, thus supporting the generation of a unified experience about and reaction to changes in the environment. Its role in schizophrenia is yet to be fully elucidated, but there is accumulating evidence that there could be differences between patients and healthy controls regarding the morphology and function of CC, especially when individuals face emotionally laden information. Here, we report a case study of a patient with partial agenesis of corpus callosum (agCC patient with agenesis of the anterior aspect, above the genu and we provide a direct comparison with a group of patients with no apparent callosal damage (CC group regarding the brain activity during the processing of emotionally-laden information. We found that although the visual cortex activation in response to visual stimuli regardless of their emotional content was comparable in agCC patient and CC group both in terms of localization and intensity of activation, we observed a very large, non-specific and non-lateralized cerebral activation in the agCC patient, in contrast with the CC group, which showed a more lateralized and spatially localized activation, when the emotional content of the stimuli was considered. Further analysis of brain activity in the regions obtained in the CC group revealed that the agCC patient actually had an opposite activation pattern relative to most participants with no CC agenesis, indicating a dysfunctional response to these kind of stimuli, consistent with the clinical presentation of this particular patient. Our results seem to give support to the disconnection hypothesis which posits that the core symptoms of schizophrenia are related to aberrant connectivity between distinct brain areas, especially when faced with emotional stimuli, a fact consistent with the clinical tableau of this particular patient.

  8. Corpus callosum size and diffusion tensor anisotropy in adolescents and adults with schizophrenia.

    Science.gov (United States)

    Balevich, Emily C; Haznedar, M Mehmet; Wang, Eugene; Newmark, Randall E; Bloom, Rachel; Schneiderman, Jason S; Aronowitz, Jonathan; Tang, Cheuk Y; Chu, King-Wai; Byne, William; Buchsbaum, Monte S; Hazlett, Erin A

    2015-03-30

    The corpus callosum has been implicated as a region of dysfunctional connectivity in schizophrenia, but the association between age and callosal pathology is unclear. Magnetic resonance imaging (MRI) and diffusion-tensor imaging (DTI) were performed on adults (n=34) and adolescents (n=17) with schizophrenia and adult (n=33) and adolescent (n=15) age- and sex-matched healthy controls. The corpus callosum was manually traced on each participant׳s MRI, and the DTI scan was co-registered to the MRI. The corpus callosum was divided into five anteroposterior segments. Area and anisotropy were calculated for each segment. Both patient groups demonstrated reduced callosal anisotropy; however, the adolescents exhibited reductions mostly in anterior regions while the reductions were more prominent in posterior regions of the adults. The adolescent patients showed greater decreases in absolute area as compared with the adult patients, particularly in the anterior segments. However, the adults showed greater reductions when area was considered relative to whole brain white matter volume. Our results suggest that the initial stages of the illness are characterized by deficiencies in frontal connections, and the chronic phase is characterized by deficits in the posterior corpus callosum; or, alternatively, adolescent-onset schizophrenia may represent a different or more severe form of the illness.

  9. Corpus callosum atrophy in patients with mild Alzheimer's disease

    DEFF Research Database (Denmark)

    Frederiksen, Kristian Steen; Garde, Ellen; Skimminge, Arnold

    2011-01-01

    Several studies have found atrophy of the corpus callosum (CC) in patients with Alzheimer's disease (AD). However, it remains unclear whether callosal atrophy is already present in the early stages of AD, and to what extent it may be associated with other structural changes in the brain, such as ......Several studies have found atrophy of the corpus callosum (CC) in patients with Alzheimer's disease (AD). However, it remains unclear whether callosal atrophy is already present in the early stages of AD, and to what extent it may be associated with other structural changes in the brain...

  10. Parenting, corpus callosum, and executive function in preschool children.

    Science.gov (United States)

    Kok, Rianne; Lucassen, Nicole; Bakermans-Kranenburg, Marian J; van IJzendoorn, Marinus H; Ghassabian, Akhgar; Roza, Sabine J; Govaert, Paul; Jaddoe, Vincent W; Hofman, Albert; Verhulst, Frank C; Tiemeier, Henning

    2014-01-01

    In this longitudinal population-based study (N = 544), we investigated whether early parenting and corpus callosum length predict child executive function abilities at 4 years of age. The length of the corpus callosum in infancy was measured using postnatal cranial ultrasounds at 6 weeks of age. At 3 years, two aspects of parenting were observed: maternal sensitivity during a teaching task and maternal discipline style during a discipline task. Parents rated executive function problems at 4 years of age in five domains of inhibition, shifting, emotional control, working memory, and planning/organizing, using the Behavior Rating Inventory of Executive Function-Preschool Version. Maternal sensitivity predicted less executive function problems at preschool age. A significant interaction was found between corpus callosum length in infancy and maternal use of positive discipline to determine child inhibition problems: The association between a relatively shorter corpus callosum in infancy and child inhibition problems was reduced in children who experienced more positive discipline. Our results point to the buffering potential of positive parenting for children with biological vulnerability.

  11. Agenesis of the corpus callosum. An autopsy study in fetuses.

    Science.gov (United States)

    Kidron, Debora; Shapira, Daniel; Ben Sira, Liat; Malinger, Gustavo; Lev, Dorit; Cioca, Andreea; Sharony, Reuven; Lerman Sagie, Tally

    2016-02-01

    Agenesis of the corpus callosum is currently diagnosed prenatally with ultrasound and MRI. While the diagnostic aspects of callosal defects are widely addressed, anatomo-histological data from fetal autopsies are sparse. Callosal defects were present in 50 fetal autopsies. Four distinct groups of complete, partial, hypoplastic, and mixed defects were determined by the gross and histologic details of the corpus callosum. These details helped to rule out other midline defects such as holoprosencephaly. Additional autopsy findings enabled specific diagnoses and suggested etiopathogeneses. Hypoplastic and mixed defects were associated with more abnormalities of the cerebral hemispheres and internal organs. The four groups did not differ according to gender, external dysmorphism, or cerebellar and brainstem anomalies. Defects were classified as syndromic (68 %), encephaloclastic (8 %), undetermined (14 %), or isolated (10 %) based on the autopsy findings. Isolated agenesis of the corpus callosum was diagnosed in only 10 % of the cases in this series, compared to higher numbers diagnosed by prenatal ultrasonography and MRI. Therefore, the autopsy, through its detailed, careful evaluation of external, as well as gross and histological internal features, can elucidate the etiopathogenesis of agenesis of the corpus callosum and suggest specific diagnoses which cannot be ascertained by prenatal imaging.

  12. Study of corpus callosum in experimental hydrocephalic wistar rats

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    Lopes Luiza da Silva

    2003-01-01

    Full Text Available PURPOSE: Hydrocephalus causes countless cerebral damages, especially on the structures around the ventricles. Hydrocephalic children present deficiencies in the nonverbal skills more than in the verbal skills, and not always revertible with an early treatment. As the corpus callosum has an important role in the nonverbal acquisition it is possible that the injuries in this structure are responsible for the cognitive dysfunctions of these children. This present study tries to establish the alterations caused by hydrocephalus on the corpus callosum of developing Wistar rats, induced by intracisternal injection of kaolin. METHODS : Seven, fourteen and twenty one days after the injection, the animals were killed, and the corpus callosum was dissected and prepared for the study of the axonal fibers. RESULTS AND CONCLUSION: The seven-day old rats in hydrocephalus development presented a delay in myelination in relation to the control rats. With the fourteen-day old rats in hydrocephalus development the corpus callosum showed a recovery of myelin, but with the twenty one-day old rats in hydrocephalus development the axonal fibers were damaged and reduced in number.

  13. Developmental changes in the corpus callosum from infancy to early adulthood: a structural magnetic resonance imaging study.

    Science.gov (United States)

    Tanaka-Arakawa, Megumi M; Matsui, Mie; Tanaka, Chiaki; Uematsu, Akiko; Uda, Satoshi; Miura, Kayoko; Sakai, Tomoko; Noguchi, Kyo

    2015-01-01

    Previous research has reported on the development trajectory of the corpus callosum morphology. However, there have been only a few studies that have included data on infants. The goal of the present study was to examine the morphology of the corpus callosum in healthy participants of both sexes, from infancy to early adulthood. We sought to characterize normal development of the corpus callosum and possible sex differences in development. We performed a morphometric magnetic resonance imaging (MRI) study of 114 healthy individuals, aged 1 month to 25 years old, measuring the size of the corpus callosum. The corpus callosum was segmented into seven subareas of the rostrum, genu, rostral body, anterior midbody, posterior midbody, isthmus and splenium. Locally weighted regression analysis (LOESS) indicated significant non-linear age-related changes regardless of sex, particularly during the first few years of life. After this increase, curve slopes gradually became flat during adolescence and adulthood in both sexes. Age of local maximum for each subarea of the corpus callosum differed across the sexes. Ratios of total corpus callosum and genu, posterior midbody, as well as splenium to the whole brain were significantly higher in females compared with males. The present results demonstrate that the developmental trajectory of the corpus callosum during early life in healthy individuals is non-linear and dynamic. This pattern resembles that found for the cerebral cortex, further suggesting that this period plays a very important role in neural and functional development. In addition, developmental trajectories and changes in growth do show some sex differences.

  14. Agenesis of the corpus callosum and autism: a comprehensive comparison.

    Science.gov (United States)

    Paul, Lynn K; Corsello, Christina; Kennedy, Daniel P; Adolphs, Ralph

    2014-06-01

    The corpus callosum, with its ∼200 million axons, remains enigmatic in its contribution to cognition and behaviour. Agenesis of the corpus callosum is a congenital condition in which the corpus callosum fails to develop; such individuals exhibit localized deficits in non-literal language comprehension, humour, theory of mind and social reasoning. These findings together with parent reports suggest that behavioural and cognitive impairments in subjects with callosal agenesis may overlap with the profile of autism spectrum disorders, particularly with respect to impairments in social interaction and communication. To provide a comprehensive test of this hypothesis, we directly compared a group of 26 adults with callosal agenesis to a group of 28 adults with a diagnosis of autism spectrum disorder but no neurological abnormality. All participants had full-scale intelligence quotient scores >78 and groups were matched on age, handedness, and gender ratio. Using the Autism Diagnostic Observation Schedule together with current clinical presentation to assess autistic symptomatology, we found that 8/26 (about a third) of agenesis subjects presented with autism. However, more formal diagnosis additionally involving recollective parent-report measures regarding childhood behaviour showed that only 3/22 met complete formal criteria for an autism spectrum disorder (parent reports were unavailable for four subjects). We found no relationship between intelligence quotient and autism symptomatology in callosal agenesis, nor evidence that the presence of any residual corpus callosum differentiated those who exhibited current autism spectrum symptoms from those who did not. Relative to the autism spectrum comparison group, parent ratings of childhood behaviour indicated children with agenesis were less likely to meet diagnostic criteria for autism, even for those who met autism spectrum criteria as adults, and even though there was no group difference in parent report of current

  15. Corpus callosum agenesis: Role of fetal magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Achour Radhouane

    2016-05-01

    Full Text Available Corpus callosum agenesis (CCA was evaluated by ultrasound examination and magnetic resonance imaging (MRI with many studies. Ultrasonography was able to suspect CCA by indirect signs but a definitive diagnosis of CCA was achieved in rare cases. MRI was able to diagnose complete CCA in majority of cases. Additional neurological abnormalities including heterotopia, gyration anomaly, asymmetry of the cerebral hemispheres, and Dandy-Walker variant were documented, as well as an ocular anomaly which was described, by MRI examination. Prenatal counseling for fetal agenesis of the corpus callosum is difficult as the prognosis is uncertain. The association with other cerebral abnormalities increases the likelihood of a poor outcome and ultrasonographic assessment of the fetal brain is limited. We found MRI to be a safe and useful additional procedure to complement ultrasonographic diagnosis or suspicion of CCA.

  16. Emotional Intelligence in Agenesis of the Corpus Callosum.

    Science.gov (United States)

    Anderson, Luke B; Paul, Lynn K; Brown, Warren S

    2017-01-23

    People with agenesis of the corpus callosum (AgCC) with normal general intelligence have deficits in complex cognitive processing, as well as in social cognition. It is uncertain the extent to which impoverished processing of emotions may contribute to social processing deficiencies. We used the Mayer-Salovey-Caruso Emotional Intelligence Test to clarify the nature of emotional intelligence in 16 adults with AgCC. As hypothesized, persons with AgCC exhibited greater disparities from norms on tests involving more socially complex aspects of emotions. The AgCC group did not differ from norms on the Experiential subscale, but they were significantly below norms on the Strategic subscale. These findings suggest that the corpus callosum is not essential for experiencing and thinking about basic emotions in a "normal" way, but is necessary for more complex processes involving emotions in the context of social interactions.

  17. Electroconvulsive Therapy and Corpus Callosum Aplasia: A 3-Year Followup

    Directory of Open Access Journals (Sweden)

    Ulrich Palm

    2011-01-01

    Full Text Available Electroconvulsive Therapy (ECT is a powerful treatment option in severe or chronic catatonic states and has been reported to be useful in oligophrenic patients. We report the followup medical history of a patient with corpus callosum aplasia (or agenesis who was continuously treated with ECT over three years. First, he improved considerably after a series of ECT, but relapses of catatonia made a continuous, weekly ECT necessary. Due to the severity of the brain malformation, an add-on medication with benzodiazepines and second generation antipsychotics was necessary to treat catatonic symptoms. This case emphasises the benefits of long-term ECT in oligophrenic patients.

  18. Corpus callosum thickness in children: an MR pattern-recognition approach on the midsagittal image.

    Science.gov (United States)

    Andronikou, Savvas; Pillay, Tanyia; Gabuza, Lungile; Mahomed, Nasreen; Naidoo, Jaishree; Hlabangana, Linda Tebogo; du Plessis, Vicci; Prabhu, Sanjay P

    2015-02-01

    Thickening of the corpus callosum is an important feature of development, whereas thinning of the corpus callosum can be the result of a number of diseases that affect development or cause destruction of the corpus callosum. Corpus callosum thickness reflects the volume of the hemispheres and responds to changes through direct effects or through Wallerian degeneration. It is therefore not only important to evaluate the morphology of the corpus callosum for congenital anomalies but also to evaluate the thickness of specific components or the whole corpus callosum in association with other findings. The goal of this pictorial review is raise awareness that the thickness of the corpus callosum can be a useful feature of pathology in pediatric central nervous system disease and must be considered in the context of the stage of development of a child. Thinning of the corpus callosum can be primary or secondary, and generalized or focal. Primary thinning is caused by abnormal or failed myelination related to the hypomyelinating leukoencephalopathies, metabolic disorders affecting white matter, and microcephaly. Secondary thinning of the corpus callosum can be caused by diffuse injury such as hypoxic-ischemic encephalopathy, human immunodeficiency virus (HIV) encephalopathy, hydrocephalus, dysmyelinating conditions and demyelinating conditions. Focal disturbance of formation or focal injury also causes localized thinning, e.g., callosal dysgenesis, metabolic disorders with localized effects, hypoglycemia, white matter injury of prematurity, HIV-related atrophy, infarction and vasculitis, trauma and toxins. The corpus callosum might be too thick because of a primary disorder in which the corpus callosum finding is essential to diagnosis; abnormal thickening can also be secondary to inflammation, infection and trauma.

  19. Corpus callosum thickness in children: an MR pattern-recognition approach on the midsagittal image

    Energy Technology Data Exchange (ETDEWEB)

    Andronikou, Savvas; Pillay, Tanyia; Gabuza, Lungile; Mahomed, Nasreen; Naidoo, Jaishree; Tebogo Hlabangana, Linda [University of the Witwatersrand, Radiology Department, Faculty of Health Sciences, Johannesburg (South Africa); Du Plessis, Vicci [University of KwaZulu-Natal, Radiology Department, Faculty of Health Sciences, Durban (South Africa); Prabhu, Sanjay P. [Harvard Medical School, Department of Radiology, Boston Children' s Hospital, Boston, MA (United States)

    2014-08-31

    Thickening of the corpus callosum is an important feature of development, whereas thinning of the corpus callosum can be the result of a number of diseases that affect development or cause destruction of the corpus callosum. Corpus callosum thickness reflects the volume of the hemispheres and responds to changes through direct effects or through Wallerian degeneration. It is therefore not only important to evaluate the morphology of the corpus callosum for congenital anomalies but also to evaluate the thickness of specific components or the whole corpus callosum in association with other findings. The goal of this pictorial review is raise awareness that the thickness of the corpus callosum can be a useful feature of pathology in pediatric central nervous system disease and must be considered in the context of the stage of development of a child. Thinning of the corpus callosum can be primary or secondary, and generalized or focal. Primary thinning is caused by abnormal or failed myelination related to the hypomyelinating leukoencephalopathies, metabolic disorders affecting white matter, and microcephaly. Secondary thinning of the corpus callosum can be caused by diffuse injury such as hypoxic-ischemic encephalopathy, human immunodeficiency virus (HIV) encephalopathy, hydrocephalus, dysmyelinating conditions and demyelinating conditions. Focal disturbance of formation or focal injury also causes localized thinning, e.g., callosal dysgenesis, metabolic disorders with localized effects, hypoglycemia, white matter injury of prematurity, HIV-related atrophy, infarction and vasculitis, trauma and toxins. The corpus callosum might be too thick because of a primary disorder in which the corpus callosum finding is essential to diagnosis; abnormal thickening can also be secondary to inflammation, infection and trauma. (orig.)

  20. Organising white matter in a brain without corpus callosum fibres.

    Science.gov (United States)

    Bénézit, Audrey; Hertz-Pannier, Lucie; Dehaene-Lambertz, Ghislaine; Monzalvo, Karla; Germanaud, David; Duclap, Delphine; Guevara, Pamela; Mangin, Jean-François; Poupon, Cyril; Moutard, Marie-Laure; Dubois, Jessica

    2015-02-01

    Isolated corpus callosum dysgenesis (CCD) is a congenital malformation which occurs during early development of the brain. In this study, we aimed to identify and describe its consequences beyond the lack of callosal fibres, on the morphology, microstructure and asymmetries of the main white matter bundles with diffusion imaging and fibre tractography. Seven children aged between 9 and 13 years old and seven age- and gender-matched control children were studied. First, we focused on bundles within the mesial region of the cerebral hemispheres: the corpus callosum, Probst bundles and cingulum which were selected using a conventional region-based approach. We demonstrated that the Probst bundles have a wider connectivity than the previously described rostrocaudal direction, and a microstructure rather distinct from the cingulum but relatively close to callosal remnant fibres. A sigmoid bundle was found in two partial ageneses. Second, the corticospinal tract, thalamic radiations and association bundles were extracted automatically via an atlas of adult white matter bundles to overcome bias resulting from a priori knowledge of the bundles' anatomical morphology and trajectory. Despite the lack of callosal fibres and the colpocephaly observed in CCD, all major white matter bundles were identified with a relatively normal morphology, and preserved microstructure (i.e. fractional anisotropy, mean diffusivity) and asymmetries. Consequently the bundles' organisation seems well conserved in brains with CCD. These results await further investigations with functional imaging before apprehending the cognition variability in children with isolated dysgenesis.

  1. Microstructural changes in thickened corpus callosum in children: contribution of magnetic resonance diffusion tensor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Merlini, Laura; Anooshiravani, Mehrak; Kanavaki, Aikaterini; Hanquinet, Sylviane [University of Geneva Children' s Hospital, Pediatric Radiology Unit, Geneva (Switzerland)

    2015-06-15

    Thickened corpus callosum is a rare finding and its pathophysiology is not well known. An anomalous supracallosal bundle has been depicted by fiber tracking in some cases but no diffusion tensor imaging metrics of thickened corpus callosum have been reported. To use diffusion tensor imaging (DTI) in cases of thickened corpus callosum to help in understanding its clinical significance. During a 7-year period five children (ages 6 months to 15 years) with thickened corpus callosum were studied. We determined DTI metrics of fractional anisotropy (FA), mean diffusivity, and axial (λ1) and radial (λ2, λ3) diffusivity and performed 3-D fiber tracking reconstruction of the thickened corpus callosum. We compared our results with data from the literature and 24 age-matched controls. Brain abnormalities were seen in all cases. All children had at least three measurements of corpus callosum thickness above the 97th percentile according to age. In all children 3-D fiber tracking showed an anomalous supracallosal bundle and statistically significant decrease in FA (P = 0.003) and λ1 (P = 0.001) of the corpus callosum compared with controls, but no significant difference in mean diffusivity and radial diffusivity. Thickened corpus callosum was associated with abnormal bundles, suggesting underlying axonal guidance abnormality. DTI metrics suggested abnormal fiber compactness and density, which may be associated with alterations in cognition. (orig.)

  2. Corpus callosum tissue loss and development of motor and global cognitive impairment

    DEFF Research Database (Denmark)

    Frederiksen, Kristian Steen; Garde, Ellen; Skimminge, Arnold;

    2011-01-01

    To examine the impact of corpus callosum (CC) tissue loss on the development of global cognitive and motor impairment in the elderly.......To examine the impact of corpus callosum (CC) tissue loss on the development of global cognitive and motor impairment in the elderly....

  3. Effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis

    Science.gov (United States)

    Feng, Liang; Jiang, Hong; Li, Yunxia; Teng, Fei; He, Yusheng

    2017-01-01

    Abstract This study aimed to investigate the effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis (LA) by diffusion tension imaging (DTI). A total of 30 LA patients with Fazekas score of 2 to 3 were voluntarily assigned into citicoline group (n = 14) and control group (n = 16). In citicoline group, citicoline was administered at 0.6 g/d for 1 year. In control group, central nervous system drugs should not be used, except for sleeping pills and antidepressants. Interventions for pre-existing diseases should be conducted in both groups. During the periods of citicoline therapy and post-treatment follow-up, cranial magnetic resonance imaging and DTI were routinely performed in these patients, and the genu, body, and splenium of corpus callosum were selected as the regions of interest (ROIs). The fractional anisotropy (FA) and mean diffusivity (MD) of each ROI were determined with PANDA software. On recruitment, there were no significant differences in the general characteristics, blood biochemical results, cognition function, and the FA and MD of the corpus callosum between 2 groups (P > 0.05). After 1-year treatment, the FA of the corpus callosum reduced gradually, but the MD of the corpus callosum tended to increased in both group, although significant differences were not observed. However, the reductions in FA of genu and splenium of corpus callosum in citicoline group were significantly lower than in control group (P < 0.05); the reductions in MD of genu, body, and splenium of corpus callosum in citicoline group were significantly lower than in control group (P < 0.05). In LA patients, the disruption of the network connectivity of the corpus callosum deteriorates over time. Citicoline treatment may delay the reduction in FA of corpus callosum, which might be beneficial for the improvement of network connectivity of the corpus callosum. PMID:28121935

  4. The corpus callosum, the other great forebrain commissures, and the septum pellucidum: anatomy, development, and malformation

    Energy Technology Data Exchange (ETDEWEB)

    Raybaud, Charles [Division of Neuroradiology, Hospital for Sick Children, Toronto, ON (Canada); University of Toronto, Division of Radiology, Toronto, ON (Canada)

    2010-06-15

    There are three telencephalic commissures which are paleocortical (the anterior commissure), archicortical (the hippocampal commissure), and neocortical. In non-placental mammals, the neocortical commissural fibers cross the midline together with the anterior and possibly the hippocampal commissure, across the lamina reuniens (joining plate) in the upper part of the lamina terminalis. In placental mammals, a phylogenetically new feature emerged, which is the corpus callosum: it results from an interhemispheric fusion line with specialized groups of mildline glial cells channeling the commissural axons through the interhemispheric meninges toward the contralateral hemispheres. This concerns the frontal lobe mainly however: commissural fibers from the temporo-occipital neocortex still use the anterior commissure to cross, and the posterior occipito-parietal fibers use the hippocampal commissure, forming the splenium in the process. The anterior callosum and the splenium fuse secondarily to form the complete commissural plate. Given the complexity of the processes involved, commissural ageneses are many and usually associated with other diverse defects. They may be due to a failure of the white matter to develop or to the commissural neurons to form or to migrate, to a global failure of the midline crossing processes or to a selective failure of commissuration affecting specific commissural sites (anterior or hippocampal commissures, anterior callosum), or specific sets of commissural axons (paleocortical, hippocampal, neocortical commissural axons). Severe hemispheric dysplasia may prevent the axons from reaching the midline on one or both sides. Besides the intrinsically neural defects, midline meningeal factors may prevent the commissuration as well (interhemispheric cysts or lipoma). As a consequence, commissural agenesis is a malformative feature, not a malformation by itself. Good knowledge of the modern embryological data may allow for a good understanding of a

  5. Ultrasound measurement of the corpus callosum and neural development of premature infants.

    Science.gov (United States)

    Liu, Fang; Cao, Shikao; Liu, Jiaoran; Du, Zhifang; Guo, Zhimei; Ren, Changjun

    2013-09-15

    Length and thickness of 152 corpus callosa were measured in neonates within 24 hours of birth. Using ultrasonic diagnostic equipment with a neonatal brain-specific probe, corpus callosum length and thickness of the genu, body, and splenium were measured on the standard mid-sagittal plane, and the anteroposterior diameter of the genu was measured in the coronal plane. Results showed that corpus callosum length as well as thickness of the genu and splenium increased with tional age and birth weight, while other measures did not. These three factors on the standard mid-sagittal plane are therefore likely to be suitable for real-time evaluation of corpus callosum velopment in premature infants using cranial ultrasound. Further analysis revealed that thickness of the body and splenium and the anteroposterior diameter of the genu were greater in male infants than in female infants, suggesting that there are sex differences in corpus callosum size during the neonatal period. A second set of measurements were taken from 40 premature infants whose gestational age was 34 weeks or less. Corpus callosum measurements were corrected to a gestational age of 40 weeks, and infants were grouped for analysis depending on the outcome of a neonatal behavioral neurological assessment. Compared with infants with a normal neurological assessment, corpus callosum length and genu and splenium thicknesses were less in those with abnormalities, indicating that corpus callosum growth in premature infants is associated with neurobehavioral development during the early extrauterine stage.

  6. Shape analysis of corpus callosum in autism subtype using planar conformal mapping

    Science.gov (United States)

    He, Qing; Duan, Ye; Yin, Xiaotian; Gu, Xianfeng; Karsch, Kevin; Miles, Judith

    2009-02-01

    A number of studies have documented that autism has a neurobiological basis, but the anatomical extent of these neurobiological abnormalities is largely unknown. In this study, we aimed at analyzing highly localized shape abnormalities of the corpus callosum in a homogeneous group of autism children. Thirty patients with essential autism and twenty-four controls participated in this study. 2D contours of the corpus callosum were extracted from MR images by a semiautomatic segmentation method, and the 3D model was constructed by stacking the contours. The resulting 3D model had two openings at the ends, thus a new conformal parameterization for high genus surfaces was applied in our shape analysis work, which mapped each surface onto a planar domain. Surface matching among different individual meshes was achieved by re-triangulating each mesh according to a template surface. Statistical shape analysis was used to compare the 3D shapes point by point between patients with autism and their controls. The results revealed significant abnormalities in the anterior most and anterior body in essential autism group.

  7. Incidentally discovered colpocephaly and corpus callosum agenesis in asymptomatic adult patient

    Directory of Open Access Journals (Sweden)

    Huseyin Buyukgol

    2016-09-01

    Full Text Available The corpus callosum is the biggest commissural structure located in two brain hemispheres and it ensures the connection between cortical and subcortical neurons. The agenesis of the corpus callosum is generally diagnosed in the prenatal period or childhood. It is observed along with congenital abnormalities such as mental and motor retardation, seizures, myelomeningocele. In this article, we reported a case of colpocephaly and corpus callosum agenesis with no symptoms that diagnosed incidentally. [Cukurova Med J 2016; 41(3.000: 564-566

  8. Abnormality of the corpus callosum in coalmine gas explosion-related posttraumatic stress disorder.

    Science.gov (United States)

    Zhang, Yang; Li, Huabing; Lang, Xu; Zhuo, Chuanjun; Qin, Wen; Zhang, Quan

    2015-01-01

    Abnormal corpus callosum (CC) has been reported in childhood trauma-related posttraumatic stress disorder (PTSD); however, the nature of white matter (WM) integrity alterations in the CC of young adult-onset PTSD patients is unknown. In this study, 14 victims of a coal mine gas explosion with PTSD and 23 matched coal miners without experiencing the coal mine explosion were enrolled. The differences in fractional anisotropy (FA) within 7 sub-regions of the CC were compared between the two groups. Compared to the controls, PTSD coal miners exhibited significantly reduced FA values in the anterior sub-regions of the CC (P < 0.05, Bonferroni-corrected), which mainly interconnect the bilateral frontal cortices. Our findings indicated that the anterior part of the CC was more severely impaired than the posterior part in young adult-onset PTSD, which suggested the patterns of CC impairment may depend on the developmental stage of the structure when the PTSD occurs.

  9. Agenesis of the corpus callosum in a newborn with Turner mosaicism

    Directory of Open Access Journals (Sweden)

    Ester Pereira

    2014-05-01

    Full Text Available The agenesis of the corpus callosum results from a failure in the development of the largest fiber bundle that connects cerebral hemispheres. Patient’s outcome is influenced by etiology and associated central nervous system malformations. We describe a child with Turner syndrome (TS mosaicism, with particular phenotype features and a complete agenesis of the corpus callosum. To our knowledge, this is the second case report of TS mosaicism associated with complete agenesis of the corpus callosum. Anatomical brain magnetic resonance imaging and diffusion tensor imaging were useful to confirm the complete absence of the corpus callosum, evaluate associated central nervous system malformations, visualize abnormal white matter tracts (Probst bundles and assess the remaining commissures.

  10. Form of the male and female corpus callosum internal organization at the mature age

    Directory of Open Access Journals (Sweden)

    Юрий Петрович Костиленко

    2016-04-01

    Full Text Available Aim: to study the special features of the male and female corpus callosum internal organization at the mature age.Materials and methods: the total preparations of the male and female corpus callosum (10 preparation of each sex at 45–60 years old were used as the material. The given preparations were used to get from it the plate cuts in the two mutually perpendicular planes with 2 mm. thick. Then the received tissue plates of the corpus callosum underwent plastination in the epoxy. Then the preparations were extracted from the non-polymerized epoxy and placed on the polyethylene film that was covered with the other film of the same size. Further this stratified block was placed amid the two glasses of the equal size that shrunk together by placing the small load on it. After the complete polymerization the received epoxy plates with the corpus callosum tissue contained in it underwent the gentle grinding and the accurate polish and as the result was obtained the surface denudation of its tissue structures that were colored with the 1 % solution of blue methylene for 1% borax solution.Results of research: at the study of the corpus callosum plastinated cuts in saggital plane was revealed that the transverse platen-form elevations of its higher surface are the cord-form tenias standing out from within and going through the corpus callosum. At its studying in the transverse cut was established that in adults can be separated two types of corpus callosum by its density: the dense one and disperse one.At the large increases of the binocular loupe (microscope MBS-9 can be seen the gaps between the adjacent commissural cords. Within it can be detected the blood vessels. On the transverse cut of commissural cords in its depth are revealed the thinnest streaks which totality consists of the two alternate dark and light lines that form the layered striation. Among the series of the light lines are visible the interlayer that separate the whole depth of

  11. Greig cephalopolysyndactyly syndrome with dysgenesis of the corpus callosum in a Bedouin family.

    Science.gov (United States)

    Marafie, M J; Temtamy, S A; Rajaram, U; al-Awadi, S A; el-Badramany, M H; Farag, T I

    1996-12-18

    We report on the first known Bedouin family with Greig cephalopolysyndactyly syndrome (MIM 175700). The index patient and his father shared pre- and postaxial polysyndactyly, mild mental retardation, and corpus callosum dysgenesis. Their phenotypic findings were compared with reported cases of both Greig cephalopolysyndactyly (GCPS) and acrocallosal syndromes. This family represents the second report of the rare occurrence of dysgenesis of the corpus callosum in GCPS.

  12. Effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis.

    Science.gov (United States)

    Feng, Liang; Jiang, Hong; Li, Yunxia; Teng, Fei; He, Yusheng

    2017-01-01

    This study aimed to investigate the effects of citicoline therapy on the network connectivity of the corpus callosum in patients with leukoaraiosis (LA) by diffusion tension imaging (DTI).A total of 30 LA patients with Fazekas score of 2 to 3 were voluntarily assigned into citicoline group (n = 14) and control group (n = 16). In citicoline group, citicoline was administered at 0.6 g/d for 1 year. In control group, central nervous system drugs should not be used, except for sleeping pills and antidepressants. Interventions for pre-existing diseases should be conducted in both groups. During the periods of citicoline therapy and post-treatment follow-up, cranial magnetic resonance imaging and DTI were routinely performed in these patients, and the genu, body, and splenium of corpus callosum were selected as the regions of interest (ROIs). The fractional anisotropy (FA) and mean diffusivity (MD) of each ROI were determined with PANDA software.On recruitment, there were no significant differences in the general characteristics, blood biochemical results, cognition function, and the FA and MD of the corpus callosum between 2 groups (P > 0.05). After 1-year treatment, the FA of the corpus callosum reduced gradually, but the MD of the corpus callosum tended to increased in both group, although significant differences were not observed. However, the reductions in FA of genu and splenium of corpus callosum in citicoline group were significantly lower than in control group (P citicoline group were significantly lower than in control group (P Citicoline treatment may delay the reduction in FA of corpus callosum, which might be beneficial for the improvement of network connectivity of the corpus callosum.

  13. Oligodendrocyte lineage and subventricular zone response to traumatic axonal injury in the corpus callosum.

    Science.gov (United States)

    Sullivan, Genevieve M; Mierzwa, Amanda J; Kijpaisalratana, Naruchorn; Tang, Haiying; Wang, Yong; Song, Sheng-Kwei; Selwyn, Reed; Armstrong, Regina C

    2013-12-01

    Traumatic brain injury frequently causes traumatic axonal injury (TAI) in white matter tracts. Experimental TAI in the corpus callosum of adult mice was used to examine the effects on oligodendrocyte lineage cells and myelin in conjunction with neuroimaging. The injury targeted the corpus callosum over the subventricular zone, a source of neural stem/progenitor cells. Traumatic axonal injury was produced in the rostral body of the corpus callosum by impact onto the skull at the bregma. During the first week after injury, magnetic resonance diffusion tensor imaging showed that axial diffusivity decreased in the corpus callosum and that corresponding regions exhibited significant axon damage accompanied by hypertrophic microglia and reactive astrocytes. Oligodendrocyte progenitor proliferation increased in the subventricular zone and corpus callosum. Oligodendrocytes in the corpus callosum shifted toward upregulation of myelin gene transcription. Plp/CreER(T):R26IAP reporter mice showed normal reporter labeling of myelin sheaths 0 to 2 days after injury but labeling was increased between 2 and 7 days after injury. Electron microscopy revealed axon degeneration, demyelination, and redundant myelin figures. These findings expand the cell types and responses to white matter injuries that inform diffusion tensor imaging evaluation and identify pivotal white matter changes after TAI that may affect axon vulnerability vs. recovery after brain injury.

  14. Axonal pathfinding mechanisms at the cortical midline and in the development of the corpus callosum

    Directory of Open Access Journals (Sweden)

    Richards L.J.

    2002-01-01

    Full Text Available The corpus callosum is a large fiber tract that connects neurons in the right and left cerebral hemispheres. Agenesis of the corpus callosum (ACC is associated with a large number of human syndromes but little is known about why ACC occurs. In most cases of ACC, callosal axons are able to grow toward the midline but are unable to cross it, continuing to grow into large swirls of axons known as Probst bundles. This phenotype suggests that in some cases ACC may be due to defects in axonal guidance at the midline. General guidance mechanisms that influence the development of axons include chemoattraction and chemorepulsion, presented by either membrane-bound or diffusible molecules. These molecules are not only expressed by the final target but by intermediate targets along the pathway, and by pioneering axons that act as guides for later arriving axons. Midline glial populations are important intermediate targets for commissural axons in the spinal cord and brain, including the corpus callosum. The role of midline glial populations and pioneering axons in the formation of the corpus callosum are discussed. Finally the differential guidance of the ipsilaterally projecting perforating pathway and the contralaterally projecting corpus callosum is addressed. Development of the corpus callosum involves the coordination of a number of different guidance mechanisms and the probable involvement of a large number of molecules.

  15. Tractography of the corpus callosum in Huntington's disease.

    Directory of Open Access Journals (Sweden)

    Owen Phillips

    Full Text Available White matter abnormalities have been shown in presymptomatic and symptomatic Huntington's disease (HD subjects using Magnetic Resonance Imaging (MRI and Diffusion Tensor Imaging (DTI methods. The largest white matter tract, the corpus callosum (CC, has been shown to be particularly vulnerable; however, little work has been done to investigate the regional specificity of tract abnormalities in the CC. Thus, this study examined the major callosal tracts by applying DTI-based tractography. Using TrackVis, a previously defined region of interest tractography method parcellating CC into seven major tracts based on target region was applied to 30 direction DTI data collected from 100 subjects: presymptomatic HD (Pre-HD subjects (n=25, HD patients (n=25 and healthy control subjects (n=50. Tractography results showed decreased fractional anisotropy (FA and increased radial diffusivity (RD across broad regions of the CC in Pre-HD subjects. Similar though more severe deficits were seen in HD patients. In Pre-HD and HD, callosal FA and RD were correlated with Disease Burden/CAG repeat length as well as motor (UHDRSI and cognitive (URDRS2 assessments. These results add evidence that CC pathways are compromised prior to disease onset with possible demyelination occurring early in the disease and suggest that CAG repeat length is a contributing factor to connectivity deficits. Furthermore, disruption of these callosal pathways potentially contributes to the disturbances of motor and cognitive processing that characterize HD.

  16. Viscoelasticity of brain corpus callosum in biaxial tension

    Science.gov (United States)

    Labus, Kevin M.; Puttlitz, Christian M.

    2016-11-01

    Computational models of the brain rely on accurate constitutive relationships to model the viscoelastic behavior of brain tissue. Current viscoelastic models have been derived from experiments conducted in a single direction at a time and therefore lack information on the effects of multiaxial loading. It is also unclear if the time-dependent behavior of brain tissue is dependent on either strain magnitude or the direction of loading when subjected to tensile stresses. Therefore, biaxial stress relaxation and cyclic experiments were conducted on corpus callosum tissue isolated from fresh ovine brains. Results demonstrated the relaxation behavior to be independent of strain magnitude, and a quasi-linear viscoelastic (QLV) model was able to accurately fit the experimental data. Also, an isotropic reduced relaxation tensor was sufficient to model the stress-relaxation in both the axonal and transverse directions. The QLV model was fitted to the averaged stress relaxation tests at five strain magnitudes while using the measured strain history from the experiments. The resulting model was able to accurately predict the stresses from cyclic tests at two strain magnitudes. In addition to deriving a constitutive model from the averaged experimental data, each specimen was fitted separately and the resulting distributions of the model parameters were reported and used in a probabilistic analysis to determine the probability distribution of model predictions and the sensitivity of the model to the variance of the parameters. These results can be used to improve the viscoelastic constitutive models used in computational studies of the brain.

  17. Acute infarction of corpus callosum due to transient obstructive hydrocephalus.

    Science.gov (United States)

    Kaymakamzade, Bahar; Eker, Amber

    2016-01-01

    Acute ischemia of the corpus callosum (CC) is not a well-known feature in patients with acute hydrocephalus. Herein, we describe a case with acute CC infarction due to another rare entity; transient obstructive hydrocephalus. A 66-year-old male was admitted with sudden onset right-sided hemiparesia. CT demonstrated a hematoma on the left basal ganglia with extension to all ventricles. The following day, the patient's neurological status progressed to coma and developed bilateral pyramidal signs. MRI demonstrated obstructive hydrocephalus and acute diffuse infarction accompanied by elevation of the CC. On the same day there was improvement in his neurological status with significant decrease in ventricular size and complete resolution of the clot in the third ventricle. The mechanism of signal abnormalities is probably related with the neural compression of the CC against the falx. Presumably, the clot causing obstruction in the third ventricle dissolved or decayed by the help of fibrinolytic activity of CSF, which was raised after IVH and caused spontaneous improvement of hydrocephalus. Bilateral neurological symptoms suggest diffuse axonal damage and normalization of the intracranial pressure should be performed on the early onset of clinical detorioration in order to prevent axonal injury.

  18. [A case of astrocytoma of corpus callosum presented diagnostic dyspraxia].

    Science.gov (United States)

    Koshimizu, K; Takeyama, E; Takeyama, E; Kizuki, H; Tei, H; Kubo, O

    1995-08-01

    A case of astrocytoma whose first clinical presentation was diagnostic dyspraxia was reported. A 38-year-old right-handed male experienced funny motion of his left hand triggered by voluntary movement of his right hand. One day, he tried to insert a coin into the vending machine with his right hand, then the left hand was against the other. One month after that event, he experienced headache and vertigo. On admission, there were no abnormal findings on neurological examination. On neuropsychological examination, he was cooperative, well orientated and attentive, and there were no callosal disconnection symptoms. Frontal lobe function tests were slightly impaired. T1-weighted MRI demonstrated irregular mixed signal intensity mass lesion extending from the genu to the body of the corpus callosum and the cingulate gyrus. This lesion was slightly enhanced with Gd-DTPA. Biopsy was performed and histological diagnosis was fibrillary astrocytoma. After irradiation and chemotherapy, he was discharged from the hospital without evident neurological deficit. About 20 cases of diagnostic dyspraxia have been reported and almost all of them were caused by cerebro-vascular disease. This is the first case of brain tumor who presented diagnostic dyspraxia.

  19. Comprehension of humor in primary agenesis of the corpus callosum.

    Science.gov (United States)

    Brown, Warren S; Paul, Lynn K; Symington, Melissa; Dietrich, Rosalind

    2005-01-01

    Individuals with agenesis of the corpus callosum (ACC) can, in some cases, perform normally on standardized intelligence tests. Nevertheless, recent studies suggest that individuals with ACC and normal IQ scores have deficits in domains of fluid and social intelligence. Anecdotal reports from families suggest diminished appreciation of the subtleties of social interactions, and deficits in the comprehension of jokes and stories. In this research, both the cartoon and narrative joke subtests of a humor test (developed by Brownell et al. [Brownell, H., Michel, D., Powelson, J., & Gardner, H. (1983). Surprise but not coherence: sensitivity to verbal humor in right-hemisphere patients. Brain and language, 18(1), 20-27] and Bihrle et al. [Bihrle, A. M., Brownell, H. H., Powelson, J. A., & Gardner, H. (1986). Comprehension of humorous and non-humorous materials by left and right brain-damaged patients. Brain and Cognition, 5(4), 399-411]) were given to 16 adults with complete ACC (all with IQs>80) and 31 controls of similar age and IQ. Individuals with ACC performed worse than controls on the narrative joke subtest (p<.025) when VIQ was controlled. However, on the cartoon subtest the two groups were not significantly different. Covarying age, forms of IQ, narrative memory, set-switching, and literal language comprehension did not substantially alter the group difference. However, covarying comprehension of nonliteral language and proverbs eliminated the difference, suggesting a common origin for the comprehension of jokes, nonliteral language, and proverbs, most likely related to capacity for understanding second-order meanings.

  20. Proverb comprehension in individuals with agenesis of the corpus callosum.

    Science.gov (United States)

    Rehmel, Jamie L; Brown, Warren S; Paul, Lynn K

    2016-09-01

    Comprehension of non-literal language involves multiple neural systems likely involving callosal connections. We describe proverb comprehension impairments in individuals with isolated agenesis of the corpus callosum (AgCC) and normal-range general intelligence. Experiment 1 compared Gorham Proverb Test (Gorham, 1956) performance in 19 adults with AgCC and 33 neurotypical control participants of similar age, sex, and intelligence. Experiment 2 used the Proverbs subtest of the Delis-Kaplan Executive Function System (D-KEFS, 2001) to compare 19 adults with AgCC and 17 control participants with similar age, sex, and intelligence. Gorham Proverbs performance was impaired in the AgCC group for both the free-response and multiple-choice tasks. On the D-KEFS proverbs test, the AgCC group performed significantly worse on the free-response task (and all derivative scores) despite normal levels of performance on the multiple-choice task. Covarying verbal intelligence did not alter these outcomes. However, covarying a measure of non-literal language comprehension considerably reduced group differences in proverb comprehension on the Gorham test, but had little effect on the D-KEFS group differences. The difference between groups seemed to be greatest when participants had to generate their own interpretation (free response), or in the multiple choice format when the test included many proverbs that were likely to be less familiar. Taken together, the results of this study clearly show that proverb comprehension is diminished in individuals with AgCC compared to their peers.

  1. Morphometry of the corpus callosum in Chinese children: relationship with gender and academic performance

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Wing Hung Alex; Chan, Yu.Lung [Prince of Wales Hospital, Department of Diagnostic Radiology and Organ Imaging, Shatin, Hong Kong (Hong Kong); Au, Kit Sum Agnes [James Cook University, Department of Psychology, Townsville, Queensland (Australia); Yeung, Ka Wai David; Kwan, Ting Fai; To, Cho Yee

    2005-06-01

    The corpus callosum has been widely studied, but no study has demonstrated whether its size and shape have any relationship with language and calculation performance. To examine the morphometry of the corpus callosum of normal Chinese children and its relationship with gender and academic performance. One hundred primary school children (63 boys, 37 girls; age 6.5-10 years) were randomly selected and the standardized academic performance for each was ascertained. On the mid-sagittal section of a brain MRI, the length, height and total area of the corpus callosum and its thickness at different sites were measured. These were correlated with sex and academic performance. Apart from the normal average dimension of the different parts of the corpus callosum, thickness at the body-splenium junction in the average-to-good performance group was significantly greater than the below-average performance group in Chinese language (P=0.005), English language (P=0.02) and mathematics (P=0.01). The remainder of the callosal thickness showed no significant relationship with academic performance. There was no significant sex difference in the thickness of any part of the corpus callosum. These findings raise the suggestion that language and mathematics proficiency may be related to the morphometry of the fibre connections in the posterior parietal lobes. (orig.)

  2. Alien hand syndrome following corpus callosum infarction: A case report and review of the literature

    Science.gov (United States)

    Gao, Xiaoyu; Li, Bing; Chu, Wenzheng; Sun, Xuwen; Sun, Chunjuan

    2016-01-01

    Alien hand syndrome (AHS) is characterized by involuntary and autonomous activity of the affected limbs, and consists of the frontal, callosal and posterior AHS variants. The callosal subtype, resulting from damage to the corpus callosum, frequently features intermanual conflict. However, infarction of the corpus callosum is rare due to abundant blood supply. The present study reported a case of AHS (callosal subtype, in the right hand) caused by callosal infarction. Infarction of the left corpus callosum was confirmed with magnetic resonance imaging. In addition, magnetic resonance angiography and digital subtraction angiography examinations revealed multiple lesions in the feeding arteries. Subsequent to antiplatelet therapy for 2 weeks following admission, the patient gradually recovered. Furthermore, the current study reviewed 31 previously reported cases of AHS following callosal infarction in the literature. PMID:27698701

  3. A cascade of morphogenic signaling initiated by the meninges controls corpus callosum formation.

    Science.gov (United States)

    Choe, Youngshik; Siegenthaler, Julie A; Pleasure, Samuel J

    2012-02-23

    The corpus callosum is the most prominent commissural connection between the cortical hemispheres, and numerous neurodevelopmental disorders are associated with callosal agenesis. By using mice either with meningeal overgrowth or selective loss of meninges, we have identified a cascade of morphogenic signals initiated by the meninges that regulates corpus callosum development. The meninges produce BMP7, an inhibitor of callosal axon outgrowth. This activity is overcome by the induction of expression of Wnt3 by the callosal pathfinding neurons, which antagonize the inhibitory effects of BMP7. Wnt3 expression in the cingulate callosal pathfinding axons is developmentally regulated by another BMP family member, GDF5, which is produced by the adjacent Cajal-Retzius neurons and turns on before outgrowth of the callosal axons. The effects of GDF5 are in turn under the control of a soluble GDF5 inhibitor, Dan, made by the meninges. Thus, the meninges and medial neocortex use a cascade of signals to regulate corpus callosum development.

  4. Alien hand syndrome following corpus callosum infarction: A case report and review of the literature.

    Science.gov (United States)

    Gao, Xiaoyu; Li, Bing; Chu, Wenzheng; Sun, Xuwen; Sun, Chunjuan

    2016-10-01

    Alien hand syndrome (AHS) is characterized by involuntary and autonomous activity of the affected limbs, and consists of the frontal, callosal and posterior AHS variants. The callosal subtype, resulting from damage to the corpus callosum, frequently features intermanual conflict. However, infarction of the corpus callosum is rare due to abundant blood supply. The present study reported a case of AHS (callosal subtype, in the right hand) caused by callosal infarction. Infarction of the left corpus callosum was confirmed with magnetic resonance imaging. In addition, magnetic resonance angiography and digital subtraction angiography examinations revealed multiple lesions in the feeding arteries. Subsequent to antiplatelet therapy for 2 weeks following admission, the patient gradually recovered. Furthermore, the current study reviewed 31 previously reported cases of AHS following callosal infarction in the literature.

  5. Meier-Gorlin syndrome with ventriculomegaly and hypoplastic corpus callosum: a rarely reported congenital malformation

    Directory of Open Access Journals (Sweden)

    Nabanita Kora

    2016-02-01

    Full Text Available Meier-Gorlin syndrome (MGS or ear-patella-short stature syndrome (MIM 224690 is a rarely reported autosomal recessive disorder having characteristic triad of microtia, short stature and aplastic or hypoplastic patella. Only 67 cases are reported. We are reporting a newborn female baby with typical features of MGS along with some other features never described before, ventriculomegaly and hypoplastic corpus callosum. We did x-rays of whole body (infantogram and MRI of brain for microcephaly. Ultrasonography of both knees showed absence of patellae and brain MRI showed ventriculomegaly and hypoplastic corpus callosum. To our best knowledge this is the second case report of MGS in India; the first reported a MGS associated with papilledema. In previously reported cases, there was no statement regarding agenesis of corpus callosum.

  6. Marchiafava-Bignami disease: magnetic resonance imaging findings in corpus callosum and subcortical white matter

    Energy Technology Data Exchange (ETDEWEB)

    Kawarabuki, Kentaro E-mail: bukky@h2.dion.ne.jp; Sakakibara, Takehiko; Hirai, Makoto; Yoshioka, Yuji; Yamamoto, Yasumasa; Yamaki, Tarumi

    2003-11-01

    A case of Marchiafava-Bignami disease (MBD) is presented using magnetic resonance imaging (MRI). A patient with a long history of alcoholism developed a gait disturbance with involuntary movements at the lower extremities. MRI scans taken at the onset showed no particular abnormalities. He progressed to a coma 10 days later. MRI scans taken 20 days after the onset showed a focal lesion at the genu of the corpus callosum and he was diagnosed as having MBD. In addition, multiple lesions were observed in bilateral frontoparietal subcortical white matter. These lesions demonstrated similar intense MRI signals as the corpus callosum.

  7. Right hand predominant constructional apraxia due to right hemisphere infarction without corpus callosum lesions.

    Science.gov (United States)

    Kobayashi, Zen; Watanabe, Mayumi; Karibe, Yuri; Nakazawa, Chika; Numasawa, Yoshiyuki; Tomimitsu, Hiroyuki; Shintani, Shuzo

    2014-01-01

    A 74-year-old right-handed woman without cognitive impairment suddenly developed nonfluent aphasia. Brain MRI showed acute infarction in the right frontal lobe and insula without involvement of the corpus callosum. A neurological examination demonstrated not only transcortical motor aphasia, but also ideomotor apraxia and right hand predominant constructional apraxia (CA). To date, right hand predominant CA has only been reported in patients with corpus callosum lesions. The right hand predominant CA observed in our patient may be associated with the failure to transfer information on the spatial structure from the right hemisphere to the motor cortex of the left hemisphere.

  8. A critical re-examination of sexual dimorphism in the corpus callosum microstructure

    DEFF Research Database (Denmark)

    Westerhausen, René; Kompus, Kristiina; Dramsdahl, Margaretha

    2011-01-01

    Recent diffusion-tensor imaging (DTI) studies suggest sexual dimorphism in the micro-structural architecture of the corpus callosum. However, the corpus callosum is also found to be larger in males than in females, a fact that might introduce a systematic bias to the analysis of DTI parameters. D...... the diffusion parameters did not correlate with regional callosal size. The present results indicate a stronger inter-hemispheric connectivity between the frontal lobes in males than females, which might be related to sex differences in hemispheric asymmetry and brain size....

  9. Corpus Callosum Area and Brain Volume in Autism Spectrum Disorder: Quantitative Analysis of Structural MRI from the ABIDE Database

    Science.gov (United States)

    Kucharsky Hiess, R.; Alter, R.; Sojoudi, S.; Ardekani, B. A.; Kuzniecky, R.; Pardoe, H. R.

    2015-01-01

    Reduced corpus callosum area and increased brain volume are two commonly reported findings in autism spectrum disorder (ASD). We investigated these two correlates in ASD and healthy controls using T1-weighted MRI scans from the Autism Brain Imaging Data Exchange (ABIDE). Automated methods were used to segment the corpus callosum and intracranial…

  10. Corpus callosum dysgenesis and lipoma: embryologic and magnetic resonance imaging aspects; Disgenesia do corpo caloso e lipoma: consideracoes embriologicas basicas e aspectos de imagem a ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Abreu Junior, Luiz de; Borri, Maria Lucia; Wolosker, Angela Maria Borri; Hartmann, Luiz Guilherme de Carvalho; Galvao Filho, Mario de Melo [Hospital e Maternidade Sao Luiz, Sao Paulo, SP (Brazil). Setor de Diagnostico por Imagem]. E-mail: abreujr@directnet.com.br; D' Ippolito, Giuseppe [Hospital e Maternidade Sao Luiz, Sao Paulo, SP (Brazil). Setor de US/TC/RMN

    2005-07-15

    The corpus callosum is the major system of association fibers that permits communication of both cerebral hemispheres. Magnetic resonance imaging has improved the study of brain malformations, including the corpus callosum dysgenesis. Lipoma is a common finding in the spectrum of corpus callosum dysgenesis. The purpose of these study was to review the embryologic events and the magnetic resonance imaging aspects related to the corpus callosum dysgenesis and to the formation of the related lipoma. (author)

  11. Functional Topography of Human Corpus Callosum: An fMRI Mapping Study

    Directory of Open Access Journals (Sweden)

    Mara Fabri

    2013-01-01

    Full Text Available The concept of a topographical map of the corpus callosum (CC has emerged from human lesion studies and from electrophysiological and anatomical tracing investigations in other mammals. Over the last few years a rising number of researchers have been reporting functional magnetic resonance imaging (fMRI activation in white matter, particularly the CC. In this study the scope for describing CC topography with fMRI was explored by evoking activation through simple sensory stimulation and motor tasks. We reviewed our published and unpublished fMRI and diffusion tensor imaging data on the cortical representation of tactile, gustatory, auditory, and visual sensitivity and of motor activation, obtained in 36 normal volunteers and in 6 patients with partial callosotomy. Activation foci were consistently detected in discrete CC regions: anterior (taste stimuli, central (motor tasks, central and posterior (tactile stimuli, and splenium (auditory and visual stimuli. Reconstruction of callosal fibers connecting activated primary gustatory, motor, somatosensory, auditory, and visual cortices by diffusion tensor tracking showed bundles crossing, respectively, through the genu, anterior and posterior body, and splenium, at sites harboring fMRI foci. These data confirm that the CC commissure has a topographical organization and demonstrate that its functional topography can be explored with fMRI.

  12. Topographic organization of V1 projections through the corpus callosum in humans.

    Science.gov (United States)

    Saenz, M; Fine, I

    2010-10-01

    The visual cortex in each hemisphere is linked to the opposite hemisphere by axonal projections that pass through the splenium of the corpus callosum. Visual-callosal connections in humans and macaques are found along the V1/V2 border where the vertical meridian is represented. Here we identify the topography of V1 vertical midline projections through the splenium within six human subjects with normal vision using diffusion-weighted MR imaging and probabilistic diffusion tractography. Tractography seed points within the splenium were classified according to their estimated connectivity profiles to topographic subregions of V1, as defined by functional retinotopic mapping. First, we report a ventral-dorsal mapping within the splenium with fibers from ventral V1 (representing the upper visual field) projecting to the inferior-anterior corner of the splenium and fibers from dorsal V1 (representing the lower visual field) projecting to the superior-posterior end. Second, we also report an eccentricity gradient of projections from foveal-to-peripheral V1 subregions running in the anterior-superior to posterior-inferior direction, orthogonal to the dorsal-ventral mapping. These results confirm and add to a previous diffusion MRI study (Dougherty et al., 2005) which identified a dorsal/ventral mapping of human splenial fibers. These findings yield a more detailed view of the structural organization of the splenium than previously reported and offer new opportunities to study structural plasticity in the visual system.

  13. Diffusion tensor MR imaging evaluation of the corpus callosum of patients with multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Rueda, Fernanda [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Servico de Radiodiagnostico; Hygino Junior, Luiz Celso; Vasconcelos, Claudia C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Programa de Pos-Graduacao em Medicina (Radiologia); Domingues, Romeu Cortes [Clinica de Diagnostico Por Imagem e Multi-Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Papais-Alvarenga, Regina M. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Gasparetto, Emerson L. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia]. E-mail: egasparetto@gmail.com

    2008-07-01

    Objective: To evaluate the fractional anisotropy (FA) values of the normal-appearing white matter of the corpus callosum (CC) in patients with relapsing-remitting multiple sclerosis (MS). Method: Fifty-seven patients with diagnosis of relapsing-remitting MS and 47 age- and gender-matched controls were studied. A conventional MR imaging protocol and a DTI sequence were performed. One neuro radiologist placed the regions of interest (ROIs) in the FA maps in five different portions of the normal-appearing CC (rostrum, genu, anterior and posterior portion of the body and splenium) in all cases. The statistical analysis was performed with the Mann-Whitney U test and p<0.05 was considered statistically significant. Results: The FA values were lower in the MS patients compared with the controls (p<0.05) in the following CC regions: rostrum (0.720 vs 0.819), anterior body (0.698 vs 0.752), posterior body (0.711 vs 0.759) and splenium (0.720 vs 0.880). Conclusion: In this series, there was a robust decrease in the FA in all regions of the normal-appearing CC, being significant in the rostrum, body and splenium. This finding suggests that there is a subtle and diffuse abnormality in the CC, which could be probably related to myelin content loss, axonal damage and gliosis. (author)

  14. Moebius syndrome with Dandy-Walker variant and agenesis of corpus callosum

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    Jomol Sara John

    2013-01-01

    Full Text Available Moebius syndrome is a rare congenital neurological disorder. The most frequent mode of presentation is facial diplegia with bilateral lateral rectus palsy, but there are variations. Here, we report a rare case of Moebius syndrome in a 15-month-old child with unilateral facial palsy, bilateral abducens nerve palsy with Dandy Walker variant, and complete agenesis of corpus callosum.

  15. Mental State Understanding in Children with Agenesis of the Corpus Callosum.

    Science.gov (United States)

    Lábadi, Beatrix; Beke, Anna M

    2017-01-01

    Impaired social functioning is a well-known outcome of individuals with agenesis of the corpus callosum. Social deficits in nonliteral language comprehension, humor, social reasoning, and recognition of facial expression have all been documented in adults with agenesis of the corpus callosum. In the present study, we examined the emotional and mentalizing deficits that contributing to the social-cognitive development in children with isolated corpus callosum agenesia, including emotion recognition, theory of mind, executive function, working memory, and behavioral impairments as assessed by the parents. The study involved children between the age of 6 and 8 years along with typically developing children who were matched by IQ, age, gender, education, and caregiver's education. The findings indicated that children with agenesis of the corpus callosum exhibited mild impairments in all social factors (recognizing emotions, understanding theory of mind), and showed more behavioral problems than control children. Taken together, these findings suggest that reduced callosal connectivity may contribute to the development of higher-order social-cognitive deficits, involving limits of complex and rapidly occurring social information to be processed. The studies of AgCC shed lights of the role of structural connectivity across the hemispheres in neurodevelopmental disorders.

  16. Intrahemispheric dysfunction in primary motor cortex without corpus callosum: a transcranial magnetic stimulation study

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    Lassonde Maryse

    2006-06-01

    Full Text Available Abstract Background The two human cerebral hemispheres are continuously interacting, through excitatory and inhibitory influences and one critical structure subserving this interhemispheric balance is the corpus callosum. Interhemispheric neurophysiological abnormalities and intrahemispheric behavioral impairments have been reported in individuals lacking the corpus callosum. The aim of this study was to examine intrahemispheric neurophysiological function in primary motor cortex devoid of callosal projections. Methods Intracortical excitatory and inhibitory systems were tested in three individuals with complete agenesis of the corpus callosum and sixteen healthy individuals. These systems were assessed using transcranial magnetic stimulation (TMS protocols: motor threshold at rest, paired-pulse curve, and cortical silent period. Results TMS revealed no difference between the patient and control groups on the motor threshold measure, as well as intracortical facilitation and intracortical inhibition systems as tested by paired stimulation. However, intrahemispheric inhibitory function was found to be abnormal in participants without callosal projections, as the cortical silent period duration was significantly increased in the patient group. Conclusion These data suggest that in addition to previously reported impaired interhemispheric function, patients lacking the entire corpus callosum also display abnormal intrahemispheric excitability of the primary motor cortex.

  17. Mental State Understanding in Children with Agenesis of the Corpus Callosum

    Science.gov (United States)

    Lábadi, Beatrix; Beke, Anna M.

    2017-01-01

    Impaired social functioning is a well-known outcome of individuals with agenesis of the corpus callosum. Social deficits in nonliteral language comprehension, humor, social reasoning, and recognition of facial expression have all been documented in adults with agenesis of the corpus callosum. In the present study, we examined the emotional and mentalizing deficits that contributing to the social-cognitive development in children with isolated corpus callosum agenesia, including emotion recognition, theory of mind, executive function, working memory, and behavioral impairments as assessed by the parents. The study involved children between the age of 6 and 8 years along with typically developing children who were matched by IQ, age, gender, education, and caregiver's education. The findings indicated that children with agenesis of the corpus callosum exhibited mild impairments in all social factors (recognizing emotions, understanding theory of mind), and showed more behavioral problems than control children. Taken together, these findings suggest that reduced callosal connectivity may contribute to the development of higher-order social-cognitive deficits, involving limits of complex and rapidly occurring social information to be processed. The studies of AgCC shed lights of the role of structural connectivity across the hemispheres in neurodevelopmental disorders. PMID:28220087

  18. Psychological Correlates of Handedness and Corpus Callosum Asymmetry in Autism: The Left Hemisphere Dysfunction Theory Revisited

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    Floris, Dorothea L.; Chura, Lindsay R.; Holt, Rosemary J.; Suckling, John; Bullmore, Edward T.; Baron-Cohen, Simon; Spencer, Michael D.

    2013-01-01

    Rightward cerebral lateralization has been suggested to be involved in the neuropathology of autism spectrum conditions. We investigated functional and neuroanatomical asymmetry, in terms of handedness and corpus callosum measurements in male adolescents with autism, their unaffected siblings and controls, and their associations with executive…

  19. Autism and Hypoplastic Corpus Callosum in a Case of Monocentric Marker Chromosome 15

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    Jovanovic-Privrodski, Jadranka D.; Kavecan, Ivana I.; Obrenovic, Milan R.; Buonadonna, Lucia A.; Bukvic, Nenad M.

    2009-01-01

    An 8-year-old boy was diagnosed with autism, along with development delay, seizures, and hypoplastic corpus callosum. His karyotype was 47, XY, +mar.ish (15) (D15Z1+, SNRPN+, GABRB3+, PML-(de novo?). The supernumerary marker chromosome 15 with euchromatin was monosatellited and monocentric. Although

  20. Age at developmental cortical injury differentially Alters corpus callosum volume in the rat

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    Rosen Glenn D

    2007-11-01

    Full Text Available Abstract Background Freezing lesions to developing rat cortex induced between postnatal day (P one and three (P1 – 3 lead to malformations similar to human microgyria, and further correspond to reductions in brain weight and cortical volume. In contrast, comparable lesions on P5 do not produce microgyric malformations, nor the changes in brain weight seen with microgyria. However, injury occurring at all three ages does lead to rapid auditory processing deficits as measured in the juvenile period. Interestingly, these deficits persist into adulthood only in the P1 lesion case 1. Given prior evidence that early focal cortical lesions induce abnormalities in cortical morphology and connectivity 1234, we hypothesized that the differential behavioral effects of focal cortical lesions on P1, P3 or P5 may be associated with underlying neuroanatomical changes that are sensitive to timing of injury. Clinical studies indicate that humans with perinatal brain injury often show regional reductions in corpus callosum size and abnormal symmetry, which frequently correspond to learning impairments 567. Therefore, in the current study the brains of P1, 3 or 5 lesion rats, previously evaluated for brain weight, and cortical volume changes and auditory processing impairments (P21-90, were further analyzed for changes in corpus callosum volume. Results Results showed a significant main effect of Treatment on corpus callosum volume [F (1,57 = 10.2, P Conclusion Decrements in corpus callosum volume in the P1 and 3 lesion groups are consistent with the reductions in brain weight and cortical volume previously reported for microgyric rats 18. Current results suggest that disruption to the cortical plate during early postnatal development may lead to more widely dispersed neurovolumetric anomalies and subsequent behavioral impairments 1, compared with injury that occurs later in development. Further, these results suggest that in a human clinical setting decreased

  1. Corpus Callosum and Neglect Syndrome: Clinical Findings After Meningioma Removal and Anatomical Review

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    Gomes, David; Fonseca, Madalena; Garrotes, Maria; Lima, Maria Rita; Mendonça, Marta; Pereira, Mariana; Lourenço, Miguel; Oliveira, Edson; Lavrador, José Pedro

    2017-01-01

    Two types of neglect are described: hemispatial and motivational neglect syndromes. Neglect syndrome is a neurophysiologic condition characterized by a malfunction in one hemisphere of the brain, resulting in contralateral hemispatial neglect in the absence of sensory loss and the right parietal lobe lesion being the most common anatomical site leading to it. In motivational neglect, the less emotional input is considered from the neglected side where anterior cingulate cortex harbors the most frequent lesions. Nevertheless, there are reports of injuries in the corpus callosum (CC) causing hemispatial neglect syndrome, particularly located in the splenium. It is essential for a neurosurgeon to recognize this clinical syndrome as it can be either a primary manifestation of neurosurgical pathology (tumor, vascular lesion) or as a postoperative iatrogenic clinical finding. The authors report a postoperative hemispatial neglect syndrome after a falcotentorial meningioma removal that recovered 10 months after surgery and performs a clinical, anatomical, and histological review centered in CC as key agent in neglect syndrome. PMID:28149091

  2. MR imaging of the corpus callosum in the patients of ischemic cerebrovascular disease

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    Umahara, Takahiko; Tanaka, Yuriko; Yamaguchi, Katsuhiko; Imamura, Toshiharu; Iwamoto, Toshihiko; Katsunuma, Hideyo (Tokyo Medical Coll. (Japan))

    1990-12-01

    We studied the abnormal MR morphology of the corpus callosum (CC) in 8 cases of progressive subcortical vascular encephalopathy (PSVE), 1 case of anterior cerebral artery (ACA) area hemorrhagic infarction, 5 cases of middle cerebral artery (MCA) area infarction, and 7 cases of posterior cerebral artery (PCA) area infarction (2 cases had bilateral PCA infarction). In addition, we studied the MR imaging of sagittal sulcal lesions of CC (SSLCC), and of inner callosal-subcallosal lesions (or inner callosal-subcallosal laminar hyperintensity; ICLH). PSVE usually showed diffuse attenuations of CC, and findings similar to a localized callosal infarction sometimes were observed. The ACA infarct case showed a rupture of the CC. The MCA infarct cases had focal attenuations (mainly at the body of the CC) caused by secondary degenerations. Only 1 of the 5 cases with unilateral PCA infarction showed a lesion in the splenium of the CC. These results are generally in accord with the results of our previous pathological study of the CC in ischemic cerebrovascular disease. Linear low signal intensity areas at the gneu found in 77% of our MRI cases, and we think these lesions compatible with SSLCC which we have studied previously. ICLH was found in the cases of PSVE, multi-infarct, and clinically normals. We therefore suggest that ICLH seems to have no disease specificity. (author).

  3. Corpus callosum thickness on mid-sagittal MRI as a marker of brain volume: a pilot study in children with HIV-related brain disease and controls

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    Andronikou, Savvas [University of the Witwatersrand, Department of Radiology, Faculty of Health Sciences, Cape Town (South Africa); Ackermann, Christelle [University of Stellenbosch, Department of Radiology, Stellenbosch (South Africa); Laughton, Barbara; Cotton, Mark [Stellenbosch University and Tygerberg Children' s Hospital, Children' s Infectious Diseases Research Unit, Stellenbosch (South Africa); Tomazos, Nicollette [University of Cape Town, Faculty of Commerce, Department of Management Studies, Cape Town (South Africa); Spottiswoode, Bruce [University of Cape Town, MRC/UCT Medical Imaging Research Unit, Department of Human Biology, Cape Town (South Africa); Mauff, Katya [University of Cape Town, Department of Statistical Sciences, Cape Town (South Africa); Pettifor, John M. [University of the Witwatersrand, MRC/Wits Developmental Pathways for Health Research Unit, Department of Paediatrics, Faculty of Health Sciences, Witwatersrand (South Africa)

    2015-07-15

    Corpus callosum thickness measurement on mid-sagittal MRI may be a surrogate marker of brain volume. This is important for evaluation of diseases causing brain volume gain or loss, such as HIV-related brain disease and HIV encephalopathy. To determine if thickness of the corpus callosum on mid-sagittal MRI is a surrogate marker of brain volume in children with HIV-related brain disease and in controls without HIV. A retrospective MRI analysis in children (<5 years old) with HIV-related brain disease and controls used a custom-developed semi-automated tool, which divided the midline corpus callosum and measured its thickness in multiple locations. Brain volume was determined using volumetric analysis. Overall corpus callosum thickness and thickness of segments of the corpus callosum were correlated with overall and segmented (grey and white matter) brain volume. Forty-four children (33 HIV-infected patients and 11 controls) were included. Significant correlations included overall corpus callosum (mean) and total brain volume (P = 0.05); prefrontal corpus callosum maximum with white matter volume (P = 0.02); premotor corpus callosum mean with total brain volume (P = 0.04) and white matter volume (P = 0.02), premotor corpus callosum maximum with white matter volume (P = 0.02) and sensory corpus callosum mean with total brain volume (P = 0.02). Corpus callosum thickness correlates with brain volume both in HIV-infected patients and controls. (orig.)

  4. Microstructural white matter changes in the corpus callosum of young people with Bipolar Disorder: a diffusion tensor imaging study.

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    Jim Lagopoulos

    Full Text Available To date, most studies of white matter changes in Bipolar Disorder (BD have been conducted in older subjects and with well-established disorders. Studies of young people who are closer to their illness onset may help to identify core neurobiological characteristics and separate these from consequences of repeated illness episodes or prolonged treatment. Diffusion tensor imaging (DTI was used to examine white matter microstructural changes in 58 young patients with BD (mean age 23 years; range 16-30 years and 40 controls. Whole brain voxelwise measures of fractional anisotropy (FA, parallel diffusivity (λ// and radial diffusivity (λ⊥ were calculated for all subjects. White matter microstructure differences (decreased FA corrected p<.05 were found between the patients with BD and controls in the genu, body and splenium of the corpus callosum as well as the superior and anterior corona radiata. In addition, significantly increased radial diffusivity (p<.01 was found in the BD group. Neuroimaging studies of young patients with BD may help to clarify neurodevelopmental aspects of the illness and for identifying biomarkers of disease onset and progression. Our findings provide evidence of microstructural white matter changes early in the course of illness within the corpus callosum and the nature of these changes suggest they are associated with abnormalities in the myelination of axons.

  5. Atrophy of the corpus callosum correlates with white matter lesions in patients with cerebral ischaemia

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    Meguro, K.; Yamadori, A. [Section of Neuropsychology, Division of Disability Science, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, 980-8575 Sendai (Japan); Constans, J.M.; Courtheoux, P.; Theron, J. [MR Unit, University of Caen School of Medicine, Caen (France); Viader, F. [Department of Neuroradiology, University of Caen School of Medicine, Caen (France)

    2000-06-01

    Many studies of white matter high signal (WMHS) on T2-weighted MRI have disclosed that it is related to cerebral ischaemia and to brain atrophy. Atrophy of the corpus callosum (CC) has also been studied in relation to ischaemia. Our objective was to test the hypothesis that CC atrophy could be due to ischaemia. We therefore assessed CC, WMHS and brain atrophy in patients with risk factors without strokes (the risk factor group) and in those with infarcts (the infarct group), to investigate the relationships between these factors. We studied 30 patients in the infarct group, 14 in the risk factor group, and 29 normal subjects. Using axial T1-weighted MRI, cortical atrophy and ventricular enlargement (brain atrophy) were visually rated. Using axial T2-weighted MRI, WMHS was assessed in three categories: periventricular symmetrical, periventricular asymmetrical and subcortical. Using the mid-sagittal T1-weighted image, the CC was measured in its anterior, posterior, midanterior and midposterior portions. In the normal group, no correlations were noted between parameters. In the infarct group, there were significant correlations between CC and brain atrophy, and between CC atrophy and WMHS. After removing the effects of age, gender and brain atrophy, significant correlations were noted between some CC measures and subcortical WMHS. In the risk factor group, there were significant correlations between CC and brain atrophy and between CC atrophy and WMHS. After allowance for age, gender and brain atrophy, significant correlations between some CC measures and periventricular WMHS remained. The hypothesis that CC atrophy could be due to cerebral ischaemia was supported by other analyses. Namely, for correlations between the extent of infarcts and partial CC atrophy in patients with anterior middle cerebral artery (MCA) and with posterior MCA infarcts, there were significant correlations between the extent of infarct and midanterior CC atrophy in the former, and posterior

  6. A novel tool for the morphometric analysis of corpus callosum: applications to the diagnosis of autism - biomed 2009

    NARCIS (Netherlands)

    Vatta, F.; Mininel, S.; Colafati, G.S.; D'Errico, L.; Malena, S.; Di Salle, F.

    2009-01-01

    Autism is a developmental disorder characterized by social deficits, impaired communication, and restricted and repetitive patterns of behaviour. Emerging theories indicate interregional functional and anatomical brain connectivity as a likely key feature in autism pathophysiology. Corpus callosum (

  7. A case of corpus callosum agenesis presenting with recurrent brief depression

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    Bhattacharyya Ranjan

    2009-01-01

    Full Text Available Agenesis of corpus callosum can have various neuropsychiatric manifestations. Following case report highlights the case of a young man presenting with features of recurrent brief depressive disorder, each lasting for about 3 to 7 days, for over a year. He had history of occasional headache and episodes of swooning attack in between, usually precipitated by emotional events. His neuroimaging revealed agenesis of corpus callosum. He was experiencing swooning attacks as he became aware that some ′unusual′ findings were present in his reports. Recurrent brief depression can be a manifestation of this congenital anomaly, and conversion disorder can be present as comorbid diagnosis perhaps due to ignorance and fear of this apparently innocuous congenital malformation.

  8. Boomerang sign: Clinical significance of transient lesion in splenium of corpus callosum

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    Hardeep Singh Malhotra

    2012-01-01

    Full Text Available Transient signal abnormality in the splenium of corpus callosum on magnetic resonance imaging (MRI is occasionally encountered in clinical practice. It has been reported in various clinical conditions apart from patients with epilepsy. We describe 4 patients with different etiologies presenting with signal changes in the splenium of corpus callosum. They were diagnosed as having progressive myoclonic epilepsy (case 1, localization-related epilepsy (case 2, hemicrania continua (case 3, and postinfectious parkinsonism (case 4. While three patients had complete involvement of the splenium on diffusion-weighted image ("boomerang sign", the patient having hemicrania continua showed semilunar involvement ("mini-boomerang" on T2-weighted and FLAIR image. All the cases had noncontiguous involvement of the splenium. We herein, discuss these cases with transient splenial involvement and stress that such patients do not need aggressive diagnostic and therapeutic interventions. An attempt has been made to review the literature regarding the pathophysiology, etiology, and outcome of such lesions.

  9. Posterior polymorphous corneal dystrophy 3 is associated with agenesis and hypoplasia of the corpus callosum.

    Science.gov (United States)

    Jang, Michelle S; Roldan, Ashley N; Frausto, Ricardo F; Aldave, Anthony J

    2014-07-01

    Posterior polymorphous corneal dystrophy (PPCD) is a dominantly inherited disorder of the corneal endothelium that has been associated with mutations in the zinc-finger E-box binding homeobox 1 gene (ZEB1) gene in approximately one-third of affected families. While the corneal dystrophies have traditionally been considered isolated disorders of the corneal endothelium, we have recently identified two cases of maldevelopment of the corpus callosum in unrelated individuals with PPCD. The proband of the first family was diagnosed shortly after birth with agenesis of the corpus callosum and several other developmental abnormalities. Karyotype, FISH and whole genome copy number variant analyses were normal. She was subsequently diagnosed with PPCD, prompting screening of the ZEB1 gene, which identified a novel deletion (c.449delG; p.(Gly150Alafs*36)) present in the heterozygous state that was not identified in either unaffected parent. The proband of the second family was diagnosed several months after birth with thinning of the corpus callosum and PPCD. Whole genome copy number variant analysis revealed a 1.79 Mb duplication of 17q12 in the proband and her father and brother, neither of whom had PPCD. ZEB1 sequencing identified a novel deletion (c.1913-1914delCA; p.(Ser638Cysfs*5)) present in the heterozygous state, which was also identified in the proband's affected mother. Thus, we report the first two cases of the association of PPCD with a developmental abnormality of the brain, in this case maldevelopment of the corpus callosum.

  10. One hundred million years of interhemispheric communication: the history of the corpus callosum

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    F. Aboitiz

    2003-04-01

    Full Text Available Analysis of regional corpus callosum fiber composition reveals that callosal regions connecting primary and secondary sensory areas tend to have higher proportions of coarse-diameter, highly myelinated fibers than callosal regions connecting so-called higher-order areas. This suggests that in primary/secondary sensory areas there are strong timing constraints for interhemispheric communication, which may be related to the process of midline fusion of the two sensory hemifields across the hemispheres. We postulate that the evolutionary origin of the corpus callosum in placental mammals is related to the mechanism of midline fusion in the sensory cortices, which only in mammals receive a topographically organized representation of the sensory surfaces. The early corpus callosum may have also served as a substrate for growth of fibers connecting higher-order areas, which possibly participated in the propagation of neuronal ensembles of synchronized activity between the hemispheres. However, as brains became much larger, the increasingly longer interhemispheric distance may have worked as a constraint for efficient callosal transmission. Callosal fiber composition tends to be quite uniform across species with different brain sizes, suggesting that the delay in callosal transmission is longer in bigger brains. There is only a small subset of large-diameter callosal fibers whose size increases with increasing interhemispheric distance. These limitations in interhemispheric connectivity may have favored the development of brain lateralization in some species like humans. "...if the currently received statements are correct, the appearance of the corpus callosum in the placental mammals is the greatest and most sudden modification exhibited by the brain in the whole series of vertebrated animals..." T.H. Huxley (1.

  11. Functional topography of the corpus callosum investigated by DTI and f MRI

    Institute of Scientific and Technical Information of China (English)

    Mara; Fabri; Chiara; Pierpaoli; Paolo; Barbaresi; Gabriele; Polonara

    2014-01-01

    This short review examines the most recent functional studies of the topographic organization of the human corpus callosum, the main interhemispheric commissure. After a brief description of its anatomy, development, microstructure, and function, it examines and discusses the latest findings obtained using diffusion tensor imaging(DTI) and tractography(DTT) and functional magnetic resonance imaging(f MRI), three recently developed imaging techniques that have significantly expanded and refined our knowledge of the commissure. While DTI and DTT have been providing insights into its microstructure, integrity and level of myelination, f MRI has been the key technique in documenting the activation of white matter fibers, particularly in the corpus callosum. By combining DTT and f MRI it has been possible to describe the trajectory of the callosal fibers interconnecting the primary olfactory, gustatory, motor, somatic sensory, auditory and visual cortices at sites where the activation elicited by peripheral stimulation was detected by fMRI. These studies have demonstrated the presence of callosal fiber tracts that cross the commissure at the level of the genu, body, and splenium, at sites showing f MRI activation. Altogether such findings lend further support to the notion that the corpus callosum displays a functional topographic organization that can be explored with f MRI.

  12. Clinical features of hereditary spastic paraplegia with thin corpus callosum:report of 5 Chinese cases

    Institute of Scientific and Technical Information of China (English)

    唐北沙; 陈昕; 赵国华; 沈璐; 严新翔; 江泓; 罗巍

    2004-01-01

    Background Hereditary spastic paraplegia is a clinically and genetically heterogeneous group of neurodegenerative disorders of the motor system, characterized by slowly progressive spasticity and weakness of the lower extremities. This study was conducted to investigate the clinical features of hereditary spastic paraplegia with thin corpus callosum (HSP-TCC). Methods Clinical data from five patients and thirty-five previously published case reports of HSP-TCC were analyzed retrospectively. Results Most patients were adolescents at the onset of the disease, presenting with spastic paraparesis of the lower limbs and mental impairment. Some patients also had other clinical features, including spasticity of the upper limbs, cerebellar ataxia, and sensory disturbances. Cranial MRIs of the five patients revealed an extremely thin corpus callosum, sometimes with widened cerebral sulci and ventricles, as well as with cerebellar and cerebral atrophy. Conclusion The main clinical features of HSP-TCC include slowly progressive spastic paraplegia, mental impairment during the second decade of life, and an extremely thin corpus callosum as shown on cranial MRIs.

  13. Reversible Restricted Diffusion in the Corpus Callosum in Various Pediatric Diseases

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    Kim, Won Kyung; Hong, Hyun Sook; Lee, A Leum; Cha, Jang Gyu; Lee, Hae Kyung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Bae, Won Kyung [Dept. of Radiology, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan (Korea, Republic of)

    2012-04-15

    To evaluate the reversible restricted diffusion in the corpus callosum in pediatric patients with clinical findings, and to discuss the possible pathogenesis of these lesions. Between 2007 and 2011, seven children with reversible signal abnormalities in the corpus callosum were identified and retrospectively reviewed. Diseases and conditions associated with lesions included: trauma (n = 3), neonatal seizure (n = 1), clinically suspected mild encephalopathy (n = 1), multiple sclerosis (n = 1), and seizure with subdural hygroma (n = 1). The callosal lesions were located in the splenium and the genu (n = 2), the splenium and the body (n = 1), and the splenium only (n 4). The shape of the lesions was round-to-ovoid (n = 4) or linear (n = 3). Follow-up MRI scans showed completely resolved (n = 6) or persistent (n = 1) signal abnormalities on diffusion-weighted imaging as well as apparent diffusion coefficient mapping. Clinical outcomes were good in six of the patents but poor in the seventh. Reversible restricted diffusion in the corpus callosum can develop in various diseases. Knowledge of the MRI findings and associated diseases might be helpful in predicting patients' conditions and clinical outcomes.

  14. Agenesis of the Corpus Callosum Due to Defective Glial Wedge Formation in Lhx2 Mutant Mice.

    Science.gov (United States)

    Chinn, Gregory A; Hirokawa, Karla E; Chuang, Tony M; Urbina, Cecilia; Patel, Fenil; Fong, Jeanette; Funatsu, Nobuo; Monuki, Edwin S

    2015-09-01

    Establishment of the corpus callosum involves coordination between callosal projection neurons and multiple midline structures, including the glial wedge (GW) rostrally and hippocampal commissure caudally. GW defects have been associated with agenesis of the corpus callosum (ACC). Here we show that conditional Lhx2 inactivation in cortical radial glia using Emx1-Cre or Nestin-Cre drivers results in ACC. The ACC phenotype was characterized by aberrant ventrally projecting callosal axons rather than Probst bundles, and was 100% penetrant on 2 different mouse strain backgrounds. Lhx2 inactivation in postmitotic cortical neurons using Nex-Cre mice did not result in ACC, suggesting that the mutant phenotype was not autonomous to the callosal projection neurons. Instead, ACC was associated with an absent hippocampal commissure and a markedly reduced to absent GW. Expression studies demonstrated strong Lhx2 expression in the normal GW and in its radial glial progenitors, with absence of Lhx2 resulting in normal Emx1 and Sox2 expression, but premature exit from the cell cycle based on EdU-Ki67 double labeling. These studies define essential roles for Lhx2 in GW, hippocampal commissure, and corpus callosum formation, and suggest that defects in radial GW progenitors can give rise to ACC.

  15. Rubinstein-Taybi syndrome with agenesis of corpus callosum.

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    Mishra, Shubhankar; Agarwalla, Sunil Kumar; Potpalle, Dnyaneshwar Ramesh; Dash, Nishant Nilotpal

    2015-01-01

    Rubinstein-Taybi syndrome (RSTS) is a rare genetic disorder with characteristic morphological anomaly. Our patient was a 4.5-year-old girl came with features like broad thumbs, downward slanting palpebral fissures and mental retardation. Systemic abnormalities such as repeated infection, seizure with developmental delay were also associated with it. She was having head banging behavior abnormal slurring speech, incoordination while transferring things from one hand to other. Galaxy of clinical pictures and magnetic resonance imaging report helped to clinch the diagnosis as a case of "RSTS with corpus callosal agenesis" which to the best of our knowledge has never been reported in past from India.

  16. Rubinstein-Taybi syndrome with agenesis of corpus callosum

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    Shubhankar Mishra

    2015-01-01

    Full Text Available Rubinstein-Taybi syndrome (RSTS is a rare genetic disorder with characteristic morphological anomaly. Our patient was a 4.5-year-old girl came with features like broad thumbs, downward slanting palpebral fissures and mental retardation. Systemic abnormalities such as repeated infection, seizure with developmental delay were also associated with it. She was having head banging behavior abnormal slurring speech, incoordination while transferring things from one hand to other. Galaxy of clinical pictures and magnetic resonance imaging report helped to clinch the diagnosis as a case of "RSTS with corpus callosal agenesis" which to the best of our knowledge has never been reported in past from India.

  17. Structural organization of the corpus callosum predicts the extent and impact of cortical activity in the nondominant hemisphere.

    Science.gov (United States)

    Putnam, Mary Colvin; Wig, Gagan S; Grafton, Scott T; Kelley, William M; Gazzaniga, Michael S

    2008-03-12

    Diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) were combined to examine the relationship between callosal organization and cortical activity across hemispheres. Healthy young adults performed an incidental verbal encoding task (semantic judgments on words) while undergoing fMRI. Consistent with previous studies, the verbal encoding task was associated with left-lateralized activity in the inferior prefrontal cortex (LIPFC). When subjects were divided into two groups based on fractional anisotropy (FA) values in the anterior corpus callosum (DTI), individuals with low anterior callosal FA were found to exhibit greater activity in a homologous region within the right inferior prefrontal cortex (RIPFC) relative to those with high anterior callosal FA. Interestingly, whereas the magnitude of RIPFC activity did not negatively impact subsequent verbal memory performance for individuals with low anterior callosal FA, greater RIPFC activity during verbal encoding was associated with poorer subsequent memory performance for individuals with high anterior callosal FA. Together, these findings provide novel evidence that individual differences in callosal organization are related to the extent of nondominant cortical activity during performance during a lateralized task, and further, that this relationship has consequences on behavior.

  18. A 54 Mb 11qter duplication and 0.9 Mb 1q44 deletion in a child with laryngomalacia and agenesis of corpus callosum

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    Lall Meena

    2011-09-01

    Full Text Available Abstract Background Partial Trisomy 11q syndrome (or Duplication 11q has defined clinical features and is documented as a rare syndrome by National Organization of Rare Disorders (NORD. Deletion 1q44 (or Monosomy 1q44 is a well-defined syndrome, but there is controversy about the genes lying in 1q44 region, responsible for agenesis of the corpus callosum. We report a female child with the rare Partial Trisomy 11q syndrome and Deletion 1q44 syndrome. The genomic imbalance in the proband was used for molecular characterization of the critical genes in 1q44 region for agenesis of corpus callosum. Some genes in 11q14q25 may be responsible for laryngomalacia. Results We report a female child with dysmorphic features, microcephaly, growth retardation, seizures, acyanotic heart disease, and hand and foot deformities. She had agenesis of corpus callosum, laryngomalacia, anterior ectopic anus, esophageal reflux and respiratory distress. Chromosome analysis revealed a derivative chromosome 1. Her karyotype was 46,XX,der(1t(1;11(q44;q14pat. The mother had a normal karyotype and the karyotype of the father was 46,XY,t(1;11(q44;q14. SNP array analysis showed that the proband had a 54 Mb duplication of 11q14q25 and a 0.9 Mb deletion of the submicroscopic subtelomeric 1q44 region. Fluorescence Insitu Hybridisation confirmed the duplication of 11qter and deletion of 1qter. Conclusion Laryngomalacia or obstruction of the upper airway is the outcome of increased dosage of some genes due to Partial Trisomy 11q Syndrome. In association with other phenotypic features, agenesis of corpus callosum appears to be a landmark phenotype for Deletion 1q44 syndrome, the critical genes lying proximal to SMYD3 in 1q44 region.

  19. PSYCHO-MOTRIC REHABILITATION IN CHILDREN WITH AGENESIS OF CORPUS CALLOSUM (Case study

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    Zărnica I. Manuela Mirela

    2011-12-01

    Full Text Available Agenesis of corpus callosum is a new challenge for the puluridisciplinary team, in their efforts for the rehabilitation of childrens with this diagnose, because is a rare congenital desease with an unknown frequence of emergence. Scope. This paperwork aims to present the approach modalities of the child with agenesis of corpus callousum and the means of physical therapy that may help. Methods. This is a case study of a 5 years old girl with asenesis of corpus callosum. For assessment we used motor assessment, range of motion, reflexes. Exercises from different positions were done as games and motric songs. Sensory stimulation was also done. Rezults. By direct observation of the patient we observed significant improvement in motor function. We also foud unexpected improvement of quiet stance and dynamic balance, sensory-motor coordination. Conclusions. Game, tha main therapeutic method through its form, diversity and characteristics - atractivity, directness, creativity, movement freedom – is the main supplement of child psicho-motric development. A balanced distribution of influences upon motricity, psychic, thinking and action, nonverbal and expression language, represent the qualitative peculiarity of specialist’s and parents efforts.

  20. Microstructural damage of the posterior corpus callosum contributes to the clinical severity of neglect.

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    Marco Bozzali

    Full Text Available One theory to account for neglect symptoms in patients with right focal damage invokes a release of inhibition of the right parietal cortex over the left parieto-frontal circuits, by disconnection mechanism. This theory is supported by transcranial magnetic stimulation studies showing the existence of asymmetric inhibitory interactions between the left and right posterior parietal cortex, with a right hemispheric advantage. These inhibitory mechanisms are mediated by direct transcallosal projections located in the posterior portions of the corpus callosum. The current study, using diffusion imaging and tract-based spatial statistics (TBSS, aims at assessing, in a data-driven fashion, the contribution of structural disconnection between hemispheres in determining the presence and severity of neglect. Eleven patients with right acute stroke and 11 healthy matched controls underwent MRI at 3T, including diffusion imaging, and T1-weighted volumes. TBSS was modified to account for the presence of the lesion and used to assess the presence and extension of changes in diffusion indices of microscopic white matter integrity in the left hemisphere of patients compared to controls, and to investigate, by correlation analysis, whether this damage might account for the presence and severity of patients' neglect, as assessed by the Behavioural Inattention Test (BIT. None of the patients had any macroscopic abnormality in the left hemisphere; however, 3 cases were discarded due to image artefacts in the MRI data. Conversely, TBSS analysis revealed widespread changes in diffusion indices in most of their left hemisphere tracts, with a predominant involvement of the corpus callosum and its projections on the parietal white matter. A region of association between patients' scores at BIT and brain FA values was found in the posterior part of the corpus callosum. This study strongly supports the hypothesis of a major role of structural disconnection between the

  1. Automatic corpus callosum segmentation using a deformable active Fourier contour model

    Science.gov (United States)

    Vachet, Clement; Yvernault, Benjamin; Bhatt, Kshamta; Smith, Rachel G.; Gerig, Guido; Cody Hazlett, Heather; Styner, Martin

    2012-03-01

    The corpus callosum (CC) is a structure of interest in many neuroimaging studies of neuro-developmental pathology such as autism. It plays an integral role in relaying sensory, motor and cognitive information from homologous regions in both hemispheres. We have developed a framework that allows automatic segmentation of the corpus callosum and its lobar subdivisions. Our approach employs constrained elastic deformation of flexible Fourier contour model, and is an extension of Szekely's 2D Fourier descriptor based Active Shape Model. The shape and appearance model, derived from a large mixed population of 150+ subjects, is described with complex Fourier descriptors in a principal component shape space. Using MNI space aligned T1w MRI data, the CC segmentation is initialized on the mid-sagittal plane using the tissue segmentation. A multi-step optimization strategy, with two constrained steps and a final unconstrained step, is then applied. If needed, interactive segmentation can be performed via contour repulsion points. Lobar connectivity based parcellation of the corpus callosum can finally be computed via the use of a probabilistic CC subdivision model. Our analysis framework has been integrated in an open-source, end-to-end application called CCSeg both with a command line and Qt-based graphical user interface (available on NITRC). A study has been performed to quantify the reliability of the semi-automatic segmentation on a small pediatric dataset. Using 5 subjects randomly segmented 3 times by two experts, the intra-class correlation coefficient showed a superb reliability (0.99). CCSeg is currently applied to a large longitudinal pediatric study of brain development in autism.

  2. White matter changes contribute to corpus callosum atrophy in the elderly: The LADIS study

    DEFF Research Database (Denmark)

    Ryberg, C.; Rostrup, E.; Sjöstrand, Karl

    2008-01-01

    BACKGROUND AND PURPOSE: The corpus callosum (CC) is the most important structure involved in the transmission of interhemispheric information. The aim of this study was to investigate the potential correlation between regional age-related white matter changes (ARWMC) and atrophy of CC in elderly...... subjects.MATERIALS AND METHODS: In 578 subjects with ARWMC from the Leukoaraiosis And DISability (LADIS) study, the cross-sectional area of the CC was automatically segmented on the normalized midsagittal MR imaging section and subdivided into 5 regions The ARWMC volumes were measured quantitatively...

  3. Estimation and Perturbation of the Mid-Sagittal Plane and its Effects on Corpus Callosum Morphometry

    DEFF Research Database (Denmark)

    Skoglund, Karl; Stegmann, Mikkel Bille; Ryberg, Charlotte

    2005-01-01

    Brain morphometry is an important tool for detecting and monitoring brain pathologies such as epilepsy, dementia [1,2] and multiple sclerosis [3]. A common method is to delineate some well-defined area of the brain to yield a shape for interor intra-subject studies. One such structure is the corpus...... callosum (CC), the white-matter nervous tissue bridging the left and right cerebral hemisphere. A multitude of papers (e.g. [2]) report on measurements performed on the two-dimensional cross-section of the CC defined by the mid-sagittal plane (MSP) which separates the left hemisphere from the right...

  4. Gorlin's syndrome with a thin corpus callosum and a third ventricular cyst

    Energy Technology Data Exchange (ETDEWEB)

    Kantarci, M.; Alper, F.; Onbas, O. [Department of Radiology, Atatuerk University School of Medicine, Erzurum (Turkey); Ertas, U. [Department of Oral and Maxillofacial Surgery, Atatuerk University School of Dentist, Erzurum (Turkey); Sutbeyaz, Y.; Karasen, R.M. [Otolaryngology, Atatuerk University School of Medicine, Otolaryngology, Erzurum (Turkey)

    2003-06-01

    Gorlin's syndrome (naevoid basal cell carcinoma) is an autosomal dominant tumor-predisposition syndrome, classically consists of multiple basal cell carcinomas of the skin, odontogenic keratocyst of the jaw, various skeletal abnormalities, and lamellar falx calcifications. Many associated lesions have been reported. We report a case of Gorlin's syndrome in a 22-year-old man in whom CT and MR images showed unusual findings of the thin corpus callosum and third ventricular cyst. We present a case of this syndrome with special emphasis on its unusual neuroradiological findings and radiological management. (orig.)

  5. Clinical significance of corpus callosum atrophy in a mixed elderly population

    DEFF Research Database (Denmark)

    Ryberg, C; Rostrup, E; Stegmann, M B;

    2007-01-01

    Corpus callosum (CC) is the main tract connecting the hemispheres, but the clinical significance of CC atrophy is poorly understood. The aim of this work was to investigate clinical and functional correlates of CC atrophy in subjects with age-related white matter changes (ARWMC). In 569 elderly......) score, history of depression, geriatric depression scale (GDS) score, subjective gait difficulty, history of falls, walking speed, and total score on the short physical performance battery (SPPB) were analyzed. Significant correlations between CC atrophy and MMSE, SPPB, and walking speed were identified...

  6. Corpus callosum abnormalities, intellectual disability, speech impairment, and autism in patients with haploinsufficiency of ARID1B

    DEFF Research Database (Denmark)

    Hansen, Christina Halgren; Kjaergaard, S; Bak, M

    2011-01-01

    of corpus callosum (CC), intellectual disability, severe speech impairment, and autism. The chromosome 6 breakpoint truncated ARID1B which was also truncated in a recently published translocation patient with a similar phenotype. Quantitative polymerase chain reaction (Q-PCR) data showed that a primer set......Corpus callosum abnormalities, intellectual disability, speech impairment, and autism in patients with haploinsufficiency of ARID1B. Corpus callosum abnormalities are common brain malformations with a wide clinical spectrum ranging from severe intellectual disability to normal cognitive function...... with various sized deletions encompassing ARID1B confirms that haploinsufficiency of ARID1B is associated with CC abnormalities, intellectual disability, severe speech impairment, and autism. Our findings emphasize that ARID1B is important in human brain development and function in general...

  7. C syndrome with skeletal anomalies, mental retardation, eyelid chalazion, Bitot’s spots and agenesis of the corpus callosum in an Egyptian child

    Directory of Open Access Journals (Sweden)

    Rabah M. Shawky

    2017-01-01

    Full Text Available We report a 2.5 year old female child, third in order of birth of healthy non consanguineous Egyptian parents with C syndrome. The patient had moderate mental retardation, trigonocephaly, protruding forehead, low anterior hair line, wide upslanted palpebral fissures, depressed nasal bridge, broad nose, high arched palate, microretrognathia, low set ears, short neck, scoliosis, hypertrichosis over the back, talipes equinovarus as well as interatrial septal defect. The patient had in addition chalazion in left lower eyelid as well as bilateral Bitot’s spots most probably due to vitamin A deficiency. MRI brain revealed agenesis of the corpus callosum.

  8. Quantitative analysis of the corpus callosum in children with cerebral palsy and developmental delay: correlation with cerebral white matter volume

    Energy Technology Data Exchange (ETDEWEB)

    Panigrahy, Ashok [Childrens Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Barnes, Patrick D. [Stanford University Medical Center, Department of Radiology, Lucile Salter Packard Children' s Hospital, Palo Alto, CA (United States); Robertson, Robert L. [Children' s Hospital Boston, Department of Radiology, Boston, MA (United States); Sleeper, Lynn A. [New England Research Institute, Watertown, MA (United States); Sayre, James W. [UCLA Medical Center, Departments of Radiology and Biostatistics, Los Angeles, CA (United States)

    2005-12-01

    This study was conducted to quantitatively correlate the thickness of the corpus callosum with the volume of cerebral white matter in children with cerebral palsy and developmental delay. Material and methods: A clinical database of 70 children with cerebral palsy and developmental delay was established with children between the ages of 1 and 5 years. These children also demonstrated abnormal periventricular T2 hyperintensities associated with and without ventriculomegaly. Mid-sagittal T1-weighted images were used to measure the thickness (genu, mid-body, and splenium) and length of the corpus callosum. Volumes of interest were digitized based on gray-scale densities to define the hemispheric cerebral white matter on axial T2-weighted and FLAIR images. The thickness of the mid-body of the corpus callosum was correlated with cerebral white matter volume. Subgroup analysis was also performed to examine the relationship of this correlation with both gestational age and neuromotor outcome. Statistical analysis was performed using analysis of variance and Pearson correlation coefficients. There was a positive correlation between the thickness of the mid-body of the corpus callosum and the volume of cerebral white matter across all children studied (R=0.665, P=0.0001). This correlation was not dependent on gestational age. The thickness of the mid-body of the corpus callosum was decreased in the spastic diplegia group compared to the two other groups (hypotonia and developmental delay only; P<0.0001). Within each neuromotor subgroup, there was a positive correlation between thickness of the mid-body of the corpus callosum and volume of the cerebral white matter. (orig.)

  9. Structural and functional reorganization of the corpus callosum between the age of 6 and 8 years.

    Science.gov (United States)

    Westerhausen, René; Luders, Eileen; Specht, Karsten; Ofte, Sonja H; Toga, Arthur W; Thompson, Paul M; Helland, Turid; Hugdahl, Kenneth

    2011-05-01

    The establishment of an efficient exchange of information between the cerebral hemispheres is of crucial importance in the developing functionally lateralized brain. The corpus callosum, the major connection between the cerebral hemispheres, grows constantly throughout childhood and adolescence. However, behavioral studies suggest the existence of a critical time period for callosal functional development starting around the age of 6 years. In the present longitudinal study, examining a cohort of 20 children at the age of 6 and 8 years, we assessed the relationship between structural and functional callosal development during this time period. The structural development was quantified by calculating the increase in callosal thickness using a shape-based computational analysis of the mid-sagittal corpus callosum as obtained with magnetic resonance imaging. The functional development was assessed with a speech discrimination task based on the dichotic presentation of consonant-vowel syllables. The statistical analysis revealed that children whose callosal isthmus increased in thickness over the course of 2 years showed a decrease in interhemispheric information transfer. However, children exhibiting a decrease in isthmus thickness revealed an increase in information transfer. These results might indicate a refinement process of the callosal connections to optimize the neuronal communication between the developing cerebral hemispheres.

  10. Genetic, morphometric, and behavioral factors linked to the midsagittal area of the corpus callosum

    Directory of Open Access Journals (Sweden)

    Alex J Newbury

    2012-05-01

    Full Text Available TThe corpus callosum is the main commissure connecting left and right cerebral hemispheres, and varies widely in size. Differences in the midsagittal area of the corpus callosum (MSACC have been associated with a number of cognitive and behavioral phenotypes, including obsessive-compulsive disorders, psychopathy, suicidal tendencies, bipolar disorder, schizophrenia, autism, and attention deficit hyperactivity disorder. Although there is evidence to suggest that MSACC is heritable in normal human populations, there is surprisingly little evidence concerning the genetic modulation of this variation. Mice provide a potentially ideal tool to dissect the genetic modulation of MSACC. Here, we use a large genetic reference panel—the BXD recombinant inbred (RI line—to dissect the natural variation of the MSACC. We estimated the MSACC in over 300 individuals from nearly 80 strains. We found a 4-fold difference in MSACC between individual mice, and a 2.5 fold difference between strains. MSACC is a highly heritable trait (h2 = 0.60, and we mapped a suggestive QTL to the distal portion of Chr 14. Using sequence data and neocortical expression databases, we were able to identify eight positional and plausible biological candidate genes within this interval. Finally, we found that MSACC correlated with behavioral traits associated with anxiety and attention.

  11. Impaired Levels of Gangliosides in the Corpus Callosum of Huntington Disease Animal Models

    Science.gov (United States)

    Di Pardo, Alba; Amico, Enrico; Maglione, Vittorio

    2016-01-01

    Huntington Disease (HD) is a genetic neurodegenerative disorder characterized by broad types of cellular and molecular dysfunctions that may affect both neuronal and non-neuronal cell populations. Among all the molecular mechanisms underlying the complex pathogenesis of the disease, alteration of sphingolipids has been identified as one of the most important determinants in the last years. In the present study, besides the purpose of further confirming the evidence of perturbed metabolism of gangliosides GM1, GD1a, and GT1b the most abundant cerebral glycosphingolipids, in the striatal and cortical tissues of HD transgenic mice, we aimed to test the hypothesis that abnormal levels of these lipids may be found also in the corpus callosum white matter, a ganglioside-enriched brain region described being dysfunctional early in the disease. Semi-quantitative analysis of GM1, GD1a, and GT1b content indicated that ganglioside metabolism is a common feature in two different HD animal models (YAC128 and R6/2 mice) and importantly, demonstrated that levels of these gangliosides were significantly reduced in the corpus callosum white matter of both models starting from the early stages of the disease. Besides corroborating the evidence of aberrant ganglioside metabolism in HD, here, we found out for the first time, that ganglioside dysfunction is an early event in HD models and it may potentially represent a critical molecular change influencing the pathogenesis of the disease. PMID:27766070

  12. Early-life stress, corpus callosum development, hippocampal volumetrics, and anxious behavior in male nonhuman primates.

    Science.gov (United States)

    Jackowski, Andrea; Perera, Tarique D; Abdallah, Chadi G; Garrido, Griselda; Tang, Cheuk Y; Martinez, Jose; Mathew, Sanjay J; Gorman, Jack M; Rosenblum, Leonard A; Smith, Eric L P; Dwork, Andrew J; Shungu, Dikoma C; Kaffman, Arie; Gelernter, Joel; Coplan, Jeremy D; Kaufman, Joan

    2011-04-30

    Male bonnet monkeys (Macaca radiata) were subjected to the variable foraging demand (VFD) early stress paradigm as infants, MRI scans were completed an average of 4 years later, and behavioral assessments of anxiety and ex-vivo corpus callosum (CC) measurements were made when animals were fully matured. VFD rearing was associated with smaller CC size, CC measurements were found to correlate with fearful behavior in adulthood, and ex-vivo CC assessments showed high consistency with earlier MRI measures. Region of interest (ROI) hippocampus and whole brain voxel-based morphometry assessments were also completed and VFD rearing was associated with reduced hippocampus and inferior and middle temporal gyri volumes. The animals were also characterized according to serotonin transporter genotype (5-HTTLPR), and the effect of genotype on imaging parameters was explored. The current findings highlight the importance of future research to better understand the effects of stress on brain development in multiple regions, including the corpus callosum, hippocampus, and other regions involved in emotion processing. Nonhuman primates provide a powerful model to unravel the mechanisms by which early stress and genetic makeup interact to produce long-term changes in brain development, stress reactivity, and risk for psychiatric disorders.

  13. The Corpus Callosum and the Visual Cortex: Plasticity Is a Game for Two

    Directory of Open Access Journals (Sweden)

    Marta Pietrasanta

    2012-01-01

    Full Text Available Throughout life, experience shapes and selects the most appropriate brain functional connectivity to adapt to a changing environment. An ideal system to study experience-dependent plasticity is the visual cortex, because visual experience can be easily manipulated. In this paper, we focus on the role of interhemispheric, transcallosal projections in experience-dependent plasticity of the visual cortex. We review data showing that deprivation of sensory experience can modify the morphology of callosal fibres, thus altering the communication between the two hemispheres. More importantly, manipulation of callosal input activity during an early critical period alters developmental maturation of functional properties in visual cortex and modifies its ability to remodel in response to experience. We also discuss recent data in rat visual cortex, demonstrating that the corpus callosum plays a role in binocularity of cortical neurons and is involved in the plastic shift of eye preference that follows a period of monocular eyelid suture (monocular deprivation in early age. Thus, experience can modify the fine connectivity of the corpus callosum, and callosal connections represent a major pathway through which experience can mediate functional maturation and plastic rearrangements in the visual cortex.

  14. Application of fractal and grey level co-occurrence matrix analysis in evaluation of brain corpus callosum and cingulum architecture.

    Science.gov (United States)

    Pantic, Igor; Dacic, Sanja; Brkic, Predrag; Lavrnja, Irena; Pantic, Senka; Jovanovic, Tomislav; Pekovic, Sanja

    2014-10-01

    This aim of this study was to assess the discriminatory value of fractal and grey level co-occurrence matrix (GLCM) analysis methods in standard microscopy analysis of two histologically similar brain white mass regions that have different nerve fiber orientation. A total of 160 digital micrographs of thionine-stained rat brain white mass were acquired using a Pro-MicroScan DEM-200 instrument. Eighty micrographs from the anterior corpus callosum and eighty from the anterior cingulum areas of the brain were analyzed. The micrographs were evaluated using the National Institutes of Health ImageJ software and its plugins. For each micrograph, seven parameters were calculated: angular second moment, inverse difference moment, GLCM contrast, GLCM correlation, GLCM variance, fractal dimension, and lacunarity. Using the Receiver operating characteristic analysis, the highest discriminatory value was determined for inverse difference moment (IDM) (area under the receiver operating characteristic (ROC) curve equaled 0.925, and for the criterion IDM≤0.610 the sensitivity and specificity were 82.5 and 87.5%, respectively). Most of the other parameters also showed good sensitivity and specificity. The results indicate that GLCM and fractal analysis methods, when applied together in brain histology analysis, are highly capable of discriminating white mass structures that have different axonal orientation.

  15. Age at First Exposure to Football Is Associated with Altered Corpus Callosum White Matter Microstructure in Former Professional Football Players.

    Science.gov (United States)

    Stamm, Julie M; Koerte, Inga K; Muehlmann, Marc; Pasternak, Ofer; Bourlas, Alexandra P; Baugh, Christine M; Giwerc, Michelle Y; Zhu, Anni; Coleman, Michael J; Bouix, Sylvain; Fritts, Nathan G; Martin, Brett M; Chaisson, Christine; McClean, Michael D; Lin, Alexander P; Cantu, Robert C; Tripodis, Yorghos; Stern, Robert A; Shenton, Martha E

    2015-11-15

    Youth football players may incur hundreds of repetitive head impacts (RHI) in one season. Our recent research suggests that exposure to RHI during a critical neurodevelopmental period prior to age 12 may lead to greater later-life mood, behavioral, and cognitive impairments. Here, we examine the relationship between age of first exposure (AFE) to RHI through tackle football and later-life corpus callosum (CC) microstructure using magnetic resonance diffusion tensor imaging (DTI). Forty retired National Football League (NFL) players, ages 40-65, were matched by age and divided into two groups based on their AFE to tackle football: before age 12 or at age 12 or older. Participants underwent DTI on a 3 Tesla Siemens (TIM-Verio) magnet. The whole CC and five subregions were defined and seeded using deterministic tractography. Dependent measures were fractional anisotropy (FA), trace, axial diffusivity, and radial diffusivity. Results showed that former NFL players in the AFE <12 group had significantly lower FA in anterior three CC regions and higher radial diffusivity in the most anterior CC region than those in the AFE ≥12 group. This is the first study to find a relationship between AFE to RHI and later-life CC microstructure. These results suggest that incurring RHI during critical periods of CC development may disrupt neurodevelopmental processes, including myelination, resulting in altered CC microstructure.

  16. Agenesis of the Corpus Callosum and Skeletal Deformities in Two Unrelated Patients: Analysis via MRI and Radiography

    Directory of Open Access Journals (Sweden)

    Ali Al Kaissi

    2014-01-01

    Full Text Available Purpose. Mental retardation, mild to severe epilepsy and cerebral palsy often of hemiplegic type are common accompaniments in patients with agenesis/hypoplasia of the corpus callosum. Skeletal deformities of bilateral radiohumeral synostosis, brachydactyly, bilateral elbow dislocation, talipes equinovarus, and juxtacalcaneal accessory bones have been encountered in two unrelated children with agenesis of the corpus callosum. Methods. We report on two unrelated children who presented with the full clinical criteria of agenesis of the corpus callosum. Strikingly, both presented with variable upper and lower limb deformities. The clinical features, radiographic and MRI findings in our current patients, have been compared with previously reported cases identified through a PubMed literature review. Results. Bilateral radiohumeral synostosis associated with pyruvate dehydrogenase deficiency has been encountered in one patient. The other patient manifested bilateral elbow dislocation, coxa valga, talipes equinovarus, and bilateral juxtacalcaneal accessory bones. Conclusion. The constellation of malformation complexes in our current patients have the hitherto not been reported and expanding the spectrum of skeletal deformities in connection with agenesis of the corpus callosum.

  17. Corpus callosum size correlates with asymmetric performance on a dichotic listening task in healthy aging but not in Alzheimer's disease

    NARCIS (Netherlands)

    Gootjes, L; Bouma, A; Van Strien, JW; Van Schijndel, R; Barkhof, F; Scheltens, P

    2006-01-01

    Alzheimer's disease (AD) involves not only gray matter but also white matter pathology, as reflected by atrophy of the corpus callosum (CC). Since decreased CC size may indicate reduced functional interhemispheric connectivity, differences in callosal size may have cognitive consequences that may be

  18. Corpus callosum size correlates with asymmetric performance on a dichotic listening task in healthy aging but not in Alzheimer's disease

    NARCIS (Netherlands)

    L. Gootjes (Liselotte); A. Bouma (Anke); J.W. van Strien (Jan); R. van Schijndel; F. Barkhof (Frederik); P. Scheltens (Philip)

    2008-01-01

    textabstractAlzheimer's disease (AD) involves not only gray matter but also white matter pathology, as reflected by atrophy of the corpus callosum (CC). Since decreased CC size may indicate reduced functional interhemispheric connectivity, differences in callosal size may have cognitive consequences

  19. Disrupted developmental organization of the structural connectome in fetuses with corpus callosum agenesis.

    Science.gov (United States)

    Jakab, András; Kasprian, Gregor; Schwartz, Ernst; Gruber, Gerlinde Maria; Mitter, Christian; Prayer, Daniela; Schöpf, Veronika; Langs, Georg

    2015-05-01

    Agenesis of the corpus callosum is a model disease for disrupted connectivity of the human brain, in which the pathological formation of interhemispheric fibers results in subtle to severe cognitive deficits. Postnatal studies suggest that the characteristic abnormal pathways in this pathology are compensatory structures that emerge via neural plasticity. We challenge this hypothesis and assume a globally different network organization of the structural interconnections already in the fetal acallosal brain. Twenty fetuses with isolated corpus callosum agenesis with or without associated malformations were enrolled and fiber connectivity among 90 brain regions was assessed using in utero diffusion tensor imaging and streamline tractography. Macroscopic scale connectomes were compared to 20 gestational age-matched normally developing fetuses with multiple granularity of network analysis. Gradually increasing connectivity strength and tract diffusion anisotropy during gestation were dominant in antero-posteriorly running paramedian and antero-laterally running aberrant pathways, and in short-range connections in the temporoparietal regions. In fetuses with associated abnormalities, more diffuse reduction of cortico-cortical and cortico-subcortical connectivity was observed than in cases with isolated callosal agenesis. The global organization of anatomical networks consisted of less segregated nodes in acallosal brains, and hubs of dense connectivity, such as the thalamus and cingulate cortex, showed reduced network centrality. Acallosal fetal brains show a globally altered connectivity network structure compared to normals. Besides the previously described Probst and sigmoid bundles, we revealed a prenatally differently organized macroconnectome, dominated by increased connectivity. These findings provide evidence that abnormal pathways are already present during at early stages of fetal brain development in the majority of cerebral white matter.

  20. The role of corpus callosum development in functional connectivity and cognitive processing.

    Directory of Open Access Journals (Sweden)

    Leighton B N Hinkley

    Full Text Available The corpus callosum is hypothesized to play a fundamental role in integrating information and mediating complex behaviors. Here, we demonstrate that lack of normal callosal development can lead to deficits in functional connectivity that are related to impairments in specific cognitive domains. We examined resting-state functional connectivity in individuals with agenesis of the corpus callosum (AgCC and matched controls using magnetoencephalographic imaging (MEG-I of coherence in the alpha (8-12 Hz, beta (12-30 Hz and gamma (30-55 Hz bands. Global connectivity (GC was defined as synchronization between a region and the rest of the brain. In AgCC individuals, alpha band GC was significantly reduced in the dorsolateral pre-frontal (DLPFC, posterior parietal (PPC and parieto-occipital cortices (PO. No significant differences in GC were seen in either the beta or gamma bands. We also explored the hypothesis that, in AgCC, this regional reduction in functional connectivity is explained primarily by a specific reduction in interhemispheric connectivity. However, our data suggest that reduced connectivity in these regions is driven by faulty coupling in both inter- and intrahemispheric connectivity. We also assessed whether the degree of connectivity correlated with behavioral performance, focusing on cognitive measures known to be impaired in AgCC individuals. Neuropsychological measures of verbal processing speed were significantly correlated with resting-state functional connectivity of the left medial and superior temporal lobe in AgCC participants. Connectivity of DLPFC correlated strongly with performance on the Tower of London in the AgCC cohort. These findings indicate that the abnormal callosal development produces salient but selective (alpha band only resting-state functional connectivity disruptions that correlate with cognitive impairment. Understanding the relationship between impoverished functional connectivity and cognition is a key

  1. Truncated Cables1 causes agenesis of the corpus callosum in mice.

    Science.gov (United States)

    Mizuno, Seiya; Tra, Dinh T H; Mizobuchi, Atsushi; Iseki, Hiroyoshi; Mizuno-Iijima, Saori; Kim, Jun-Dal; Ishida, Junji; Matsuda, Yoichi; Kunita, Satoshi; Fukamizu, Akiyoshi; Sugiyama, Fumihiro; Yagami, Ken-ichi

    2014-03-01

    Agenesis of the corpus callosum (ACC) is a congenital abnormality of the brain structure. More than 60 genes are known to be involved in corpus callosum development. However, the molecular mechanisms underlying ACC are not fully understood. Previously, we produced a novel transgenic mouse strain, TAS, carrying genes of the tetracycline-inducible expression system that are not involved in brain development, and inherited ACC was observed in the brains of all homozygous TAS mice. Although ACC was probably induced by transgene insertion mutation, the causative gene and the molecular mechanism of its pathogenesis remain unclear. Here, we first performed interphase three-color fluorescence in situ hybridization (FISH) analysis to determine the genomic insertion site. Transgenes were inserted into chromosome 18 ∼12.0 Mb from the centromere. Gene expression analysis and genomic PCR walking showed that the genomic region containing exon 4 of Cables1 was deleted by transgene insertion and the other exons of Cables1 were intact. The mutant allele was designated as Cables1(TAS). Interestingly, Cables1(TAS) mRNA consisted of exons 1-3 of Cables1 and part of the transgene that encoded a novel truncated Cables1 protein. Homozygous TAS mice exhibited mRNA expression of Cables1(TAS) in the fetal cerebrum, but not that of wild-type Cables1. To investigate whether a dominant negative effect of Cables1(TAS) or complete loss of function of Cables1 gives rise to ACC, we produced Cables1-null mutant mice. ACC was not observed in Cables1-null mutant mice, suggesting that a dominant negative effect of Cables1(TAS) impairs callosal formation. Moreover, ACC frequency in Cables1(+/TAS) mice was significantly lower than that in Cables1(-/TAS) mice, indicating that wild-type Cables1 interfered with the dominant negative effect of Cables1(TAS). This study indicated that truncated Cables1 causes ACC and wild-type Cables1 contributes to callosal formation.

  2. Working memory and corpus callosum microstructural integrity after pediatric traumatic brain injury: a diffusion tensor tractography study.

    Science.gov (United States)

    Treble, Amery; Hasan, Khader M; Iftikhar, Amal; Stuebing, Karla K; Kramer, Larry A; Cox, Charles S; Swank, Paul R; Ewing-Cobbs, Linda

    2013-10-01

    Deficits in working memory (WM) are a common consequence of pediatric traumatic brain injury (TBI) and are believed to contribute to difficulties in a range of cognitive and academic domains. Reduced integrity of the corpus callosum (CC) after TBI may disrupt the connectivity between bilateral frontoparietal neural networks underlying WM. In the present investigation, diffusion tensor imaging (DTI) tractography of eight callosal subregions (CC1-CC8) was examined in relation to measures of verbal and visuospatial WM in 74 children sustaining TBI and 49 typically developing comparison children. Relative to the comparison group, children with TBI demonstrated poorer visuospatial WM, but comparable verbal WM. Microstructure of the CC was significantly compromised in brain-injured children, with lower fractional anisotropy (FA) and higher axial and radial diffusivity metrics in all callosal subregions. In both groups of children, lower FA and/or higher radial diffusivity in callosal subregions connecting anterior and posterior parietal cortical regions predicted poorer verbal WM, whereas higher radial diffusivity in callosal subregions connecting anterior and posterior parietal, as well as temporal, cortical regions predicted poorer visuospatial WM. DTI metrics, especially radial diffusivity, in predictive callosal subregions accounted for significant variance in WM over and above remaining callosal subregions. Reduced microstructural integrity of the CC, particularly in subregions connecting parietal and temporal cortices, may act as a neuropathological mechanism contributing to long-term WM deficits. The future clinical use of neuroanatomical biomarkers may allow for the early identification of children at highest risk for WM deficits and earlier provision of interventions for these children.

  3. Bart’s Syndrome Associated Corpus Callosum Agenesis and Choanal Atresia

    Directory of Open Access Journals (Sweden)

    Muhammad SAEED*

    2014-12-01

    Full Text Available How to Cite This Article: Saeed M, Haq A, Qadir Kh.Bart’s Syndrome Associated Corpus Callosum Agenesis and Choanal Atresia. Iran J Child Neurol. 2014 Autumn;8(4: 76-79.AbstractObjectiveBart’s syndrome is defined as congenital localized absence of skin, and associated with epidermolysis bullosa. A newborn with Bart’s syndrome is reported because it is a very rare condition, especially when associated with corpus callosum agenesis and concomitant choanal atresia. Clinically it is characterized by raw beefy areas of denuded skin mainly on hands and feet.We report a rare case of a term female newborn born to non-consanguineous parents who presented with congenital absence of skin in, face, trunk and extremities. To the best of our knowledge, this is the first report presenting a case of Bart’s syndrome associated with corpus callosum agenesis.ReferencesBart BJ, Garlin RJ, Anderson VE, Lynch FW. Congenital localized absence of skin and associated abnormalities resembling epidermolysis bullosa. A new syndrome. Arch Dermatol 1966; 93: 296-304.Bart BJ. Epidermolysis bullosa and congenital localized absence of skin. Arch Dermatol 1970; 101: 78-81.Skoven I, Drzewiecki KT. Congenital localized skin defect and epidermolysis bullosa hereditaria letalis. Acta Derm Venereol 1979; 59: 533-537.Wojnarowska FT, Eady RA, Wells RS. Dystrophic epidermolysis bullosa presenting with congenital localized absence of skin: report of four cases. Br J Dermatol 1983; 108: 477-483.Kanzler MH, Smoller B, Woodley DT. Congenital localized absence of the skin as a manifestation of epidermolysis bullosa. Arch Dermatol 1992; 128:1087-90.Maman E, Maor E, Kachko L, Carmi R. Epidermolysis bullosa, pyloric atresia, aplasia cutis congenita: histopathological delineation of an autosomal recessive disease. Am J Med Genet 1998; 78: 127-133.McCarthy MA, Clarke T, Powell FC. Epidermolysis bullosa and aplasia cutis. Int J Derm 1991; 30: 481-484.Puvabanditsin S, Garrow E, Daeun K

  4. Acute infarct of the corpus callosum presenting as alien hand syndrome: evidence of diffusion weighted imaging and magnetic resonance angiography

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    Yuan Jun

    2011-11-01

    Full Text Available Abstract Background Infarcts of the corpus callosum are rare and have not been well documented previously. As for a variety of signs and symptoms presented, alien hand syndrome (AHS can be easily overlooked. Case presentation In this report, we present a patient with a mixed types of AHS coexistence secondary to the corpus callosum infarction, including a motor type of AHS by intermanual conflict (callosal type AHS and a sensory type of AHS by alien hand and left hemianesthesia (posterior AHS. Conclusions Our case may contribute to the early recognition of AHS and to explore the abnormal neural mechanism of AHS. To our knowledge, rare reports have ever documented such mixed AHS coexisting secondary to the callosal lesion, based on advanced neuroimaging methods as in our case.

  5. Astroglial-Mediated Remodeling of the Interhemispheric Midline Is Required for the Formation of the Corpus Callosum

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    Ilan Gobius

    2016-10-01

    Full Text Available The corpus callosum is the major axon tract that connects and integrates neural activity between the two cerebral hemispheres. Although ∼1:4,000 children are born with developmental absence of the corpus callosum, the primary etiology of this condition remains unknown. Here, we demonstrate that midline crossing of callosal axons is dependent upon the prior remodeling and degradation of the intervening interhemispheric fissure. This remodeling event is initiated by astroglia on either side of the interhemispheric fissure, which intercalate with one another and degrade the intervening leptomeninges. Callosal axons then preferentially extend over these specialized astroglial cells to cross the midline. A key regulatory step in interhemispheric remodeling is the differentiation of these astroglia from radial glia, which is initiated by Fgf8 signaling to downstream Nfi transcription factors. Crucially, our findings from human neuroimaging studies reveal that developmental defects in interhemispheric remodeling are likely to be a primary etiology underlying human callosal agenesis.

  6. Cerebral Visual Impairment and Dysgenesis of Corpus Callosum in Multidisabled Children Aged 1 to 9 Years Old

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    Roxana CZIKER

    2009-12-01

    Full Text Available Aims: To emphasize the functional vision characteristics in visually impaired multiple disabled children (MDVI aged 2 to 9 years old related to brain damages on magnetic resonance imaging in different cortical and subcortical areas and in the corpus callosum region. Material and Method: 12 MDVI children with severe and mild neurological disorders were medically and neuropsychological assessed. The clinical - psychological, neurological and ophthalmological – and paraclinical methods – visual evoked potential (VEP and magnetic resonance imaging (MRI were carried out in order to outline the complete profile of each child. The assessment was completed by morphometric measurement of corpus callosum and brain. Results: 10 of infants with severe neurological disorders showed ocular disorders such as ocular motility and visual function abnormalities. Severe cognitive and psychomotor retardation were associated in visual disorders in MDVI children. Significant correlation between neurological disorders, neuropsychological [τ(12 = 0.783, p = 0.001] evaluation and visual acuity [τ(12 = 0.783, p = 0.001] were found in multiple disabled children. The significant difference of diameter [t(22 = -4.858, p = 0.000] and surface of corpus callosum [t(22 = -6.254, p = 0.000] in multiple disabled children compared with control group was found. Conclusion: The structured assessment of visually impaired children due to neurological disorders, as early as possible, is the remarkably key which reveals the functionality of child and outlines the appropriate developmental and educational rehabilitation.

  7. A reversible lesion of the corpus callosum splenium with adult influenza-associated encephalitis/encephalopathy: a case report

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    Kimura En

    2008-06-01

    Full Text Available ABstract Introduction Influenza virus-associated encephalitis/encephalopathy is a severe childhood illness with a poor prognosis. Adult case reports are rare and, to date, there have been no reports of adults with a mild subcortical encephalopathy with reversible lesions of the corpus callosum splenium. Case presentation A previously healthy 35-year-old man presented with acute progressive tetraplegia, transcortical motor aphasia and a mild decrease in his consciousness during his recovery after receiving oseltamivir phosphate treatment, and influenza type A antiviral medication. The initial magnetic resonance imaging study at day 1 showed symmetrical diffuse lesions in the white matter and a lesion on the central portion of the corpus callosum splenium. These findings had resolved on follow-up studies at day 8 and day 146. His neurological deficits mostly recovered within 12 hours following methylprednisolone pulse therapy. The levels of interleukin-6 and interleukin-10 in his blood and cerebrospinal fluid were initially elevated, but rapidly decreased to normal levels by day 8. Conclusion It is important for clinicians to recognize that even in adulthood, the subcortical encephalopathy observed during the therapeutic treatment for influenza type A infection can occur in conjunction with a reversible lesion of the corpus callosum, which may recover quickly. In addition, the cytokine storm in the blood system and the corticospinal cavity may play an important role in the etiology of the disease process.

  8. Abnormal pathways in the genu of the corpus callosum in schizophrenia pathogenesis: a proteome study.

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    Sivagnanasundaram, Sinthuja; Crossett, Ben; Dedova, Irina; Cordwell, Stuart; Matsumoto, Izuru

    2007-10-01

    Abnormalities within the corpus callosum (CC) have been identified in schizophrenia brains and are thought to affect inter-hemispheric communication, which in-turn is postulated to underlie some schizophrenia symptoms. Furthermore, hemisphere asymmetry of fractional anisotropy, detected by diffusion tensor imaging, left-higher-than-right- has been observed in normal individuals in the CC genu. This asymmetry is significantly reduced in the left CC genu of first-episode and chronic schizophrenia subjects. We examined the protein expression profile of the CC genu, including the profiles from the left and right hemisphere, in schizophrenia brains compared to controls using two-dimensional gel electrophoresis and mass spectrometry techniques. Proteins involved in cytoskeletal structure and function, neuroprotective function and energy metabolism were identified as differentially expressed, suggesting these proteins may underlie abnormal CC genu structure and function. Proteins in these functional categories also displayed different expression levels in the left CC genu compared to the right in both control and schizophrenia brains and therefore may be involved in normal CC asymmetry and reduced asymmetry in schizophrenia individuals. This initial pool of protein candidates and abnormal functional pathways opens up avenues for further investigation of molecular mechanisms involving the CC in schizophrenia pathogenesis and symptoms.

  9. Progesterone and nestorone promote myelin regeneration in chronic demyelinating lesions of corpus callosum and cerebral cortex.

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    El-Etr, Martine; Rame, Marion; Boucher, Celine; Ghoumari, Abdel M; Kumar, Narender; Liere, Philippe; Pianos, Antoine; Schumacher, Michael; Sitruk-Ware, Regine

    2015-01-01

    Multiple Sclerosis affects mainly women and consists in intermittent or chronic damages to the myelin sheaths, focal inflammation, and axonal degeneration. Current therapies are limited to immunomodulators and antiinflammatory drugs, but there is no efficient treatment for stimulating the endogenous capacity of myelin repair. Progesterone and synthetic progestins have been shown in animal models of demyelination to attenuate myelin loss, reduce clinical symptoms severity, modulate inflammatory responses and partially reverse the age-dependent decline in remyelination. Moreover, progesterone has been demonstrated to promote myelin formation in organotypic cultures of cerebellar slices. In the present study, we show that progesterone and the synthetic 19-nor-progesterone derivative Nestorone® promote the repair of severe chronic demyelinating lesions induced by feeding cuprizone to female mice for up to 12 weeks. Progesterone and Nestorone increase the density of NG2(+) oligodendrocyte progenitor cells and CA II(+) mature oligodendrocytes and enhance the formation of myelin basic protein (MBP)- and proteolipid protein (PLP)-immunoreactive myelin. However, while demyelination in response to cuprizone was less marked in corpus callosum than in cerebral cortex, remyelination appeared earlier in the former. The remyelinating effect of progesterone was progesterone receptor (PR)-dependent, as it was absent in PR-knockout mice. Progesterone and Nestorone also decreased (but did not suppress) neuroinflammatory responses, specifically astrocyte and microglial cell activation. Therefore, some progestogens are promising therapeutic candidates for promoting the regeneration of myelin.

  10. Focal transient lesion in the splenium of the corpus callosum in three non-epileptic patients

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    Rocha, Antonio Jose da; Pereira Pinto Gama, Hugo; Silva, Carlos Jorge da; Braga, Flavio Tulio [Santa Casa de Misericordia de Sao Paulo, Section of Radiology, Centro de Medicina Diagnostica Fleury, Sao Paulo (Brazil); Reis, Fabiano [State University of Campinas, Department of Radiology, Campinas (Brazil); Martins Maia, Antonio Carlos Junior [Federal University of Sao Paulo, Centro de Medicina Diagnostica Fleury, Department of Neurology, Escola Paulista de Medicina, Sao Paulo (Brazil); Cendes, Fernando [State University of Campinas, Department of Neurology, Campinas (Brazil)

    2006-10-15

    We analyzed the imaging features of transient focal lesions in the splenium of the corpus callosum (SCC) in non-epileptic patients receiving antiepileptic drugs (AEDs). We identified signal abnormalities in the SCC in three non-epileptic patients, all of them receiving AEDs. We examined two of these patients with multiplanar magnetic resonance (MR) imaging using 1.0-T equipment including fluid-attenuated inversion recovery (FLAIR), T2-weighted (TSE) and T1-weighted (SE) sequences before and after injection of contrast agent. The third patient was studied using 1.5-T equipment with the same sequences. Additionally, a T1 SE sequence with a magnetization transfer contrast pulse off resonance (T1 SE/MTC), diffusion-weighted imaging (EPI-DWI) and apparent diffusion coefficient (ADC) maps were obtained. We observed an identical pattern of imaging abnormalities in all patients characterized by round lesions, hyperintense on FLAIR and hypointense on T1 SE images, located in the central portion of the SCC. One lesion showed homogeneous gadolinium enhancement and perilesional vasogenic edema. This particular lesion showed restricted diffusion confirmed on the ADC map. This pattern was considered consistent with focal demyelination. Follow-up MR examinations showed complete disappearance or a clear reduction in lesion size. All patients had been treated with AEDs, but they did not show any clinical signs of toxicity, interhemispheric symptoms, or abnormal neurological findings (including seizures). (orig.)

  11. The tumor suppressor Nf2 regulates corpus callosum development by inhibiting the transcriptional coactivator Yap.

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    Lavado, Alfonso; Ware, Michelle; Paré, Joshua; Cao, Xinwei

    2014-11-01

    The corpus callosum connects cerebral hemispheres and is the largest axon tract in the mammalian brain. Callosal malformations are among the most common congenital brain anomalies and are associated with a wide range of neuropsychological deficits. Crossing of the midline by callosal axons relies on a proper midline environment that harbors guidepost cells emitting guidance cues to instruct callosal axon navigation. Little is known about what controls the formation of the midline environment. We find that two components of the Hippo pathway, the tumor suppressor Nf2 (Merlin) and the transcriptional coactivator Yap (Yap1), regulate guidepost development and expression of the guidance cue Slit2 in mouse. During normal brain development, Nf2 suppresses Yap activity in neural progenitor cells to promote guidepost cell differentiation and prevent ectopic Slit2 expression. Loss of Nf2 causes malformation of midline guideposts and Slit2 upregulation, resulting in callosal agenesis. Slit2 heterozygosity and Yap deletion both restore callosal formation in Nf2 mutants. Furthermore, selectively elevating Yap activity in midline neural progenitors is sufficient to disrupt guidepost formation, upregulate Slit2 and prevent midline crossing. The Hippo pathway is known for its role in controlling organ growth and tumorigenesis. Our study identifies a novel role of this pathway in axon guidance. Moreover, by linking axon pathfinding and neural progenitor behaviors, our results provide an example of the intricate coordination between growth and wiring during brain development.

  12. A Case of a Newborn with Agenesis of the Corpus Callosum Complicated with Ocular Albinism

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    Michiko Miki

    2016-05-01

    Full Text Available Purpose: To report a case of ocular albinism found in a newborn infant in whom agenesis of the corpus callosum (ACC was indicated in utero. Case Report: This study involved a female newborn who was delivered after a gestational period of 41 weeks. The patient was referred to the Obstetrics Department at Takatsuki Hospital, Takatsuki City, Japan, after the indication of ACC by magnetic resonance imaging (MRI at a nearby clinic during the fetal period. At birth, the baby’s weight was 2,590 g, and ACC and ventricular enlargement were found by cranial sonography and cranial MRI. While initial ophthalmic findings noted partial loss of pigmentation of the iris and hypopigmentation of broad areas of the fundus in both eyes, nystagmus was not observed. The patient’s hair pigment was slightly diluted, and the color of her skin was slightly off-white. At 2 years after birth, obvious mental retardation was observed. With regard to other systemic findings, no apparent heart, kidney, or immune system abnormalities were found. Conclusion: Although the patient in question is presently growing without any major systemic problems, it will be necessary in the future to pay attention to any changes in systemic and ophthalmic findings.

  13. Dehydration-Induced Anorexia Reduces Astrocyte Density in the Rat Corpus Callosum

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    Daniel Reyes-Haro

    2015-01-01

    Full Text Available Anorexia nervosa is an eating disorder associated with severe weight loss as a consequence of voluntary food intake avoidance. Animal models such as dehydration-induced anorexia (DIA mimic core features of the disorder, including voluntary reduction in food intake, which compromises the supply of energy to the brain. Glial cells, the major population of nerve cells in the central nervous system, play a crucial role in supplying energy to the neurons. The corpus callosum (CC is the largest white matter tract in mammals, and more than 99% of the cell somata correspond to glial cells in rodents. Whether glial cell density is altered in anorexia is unknown. Thus, the aim of this study was to estimate glial cell density in the three main regions of the CC (genu, body, and splenium in a murine model of DIA. The astrocyte density was significantly reduced (~34% for the DIA group in the body of the CC, whereas in the genu and the splenium no significant changes were observed. DIA and forced food restriction (FFR also reduced the ratio of astrocytes to glial cells by 57.5% and 22%, respectively, in the body of CC. Thus, we conclude that DIA reduces astrocyte density only in the body of the rat CC.

  14. Dehydration-Induced Anorexia Reduces Astrocyte Density in the Rat Corpus Callosum

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    Reyes-Haro, Daniel; Labrada-Moncada, Francisco Emmanuel; Miledi, Ricardo; Martínez-Torres, Ataúlfo

    2015-01-01

    Anorexia nervosa is an eating disorder associated with severe weight loss as a consequence of voluntary food intake avoidance. Animal models such as dehydration-induced anorexia (DIA) mimic core features of the disorder, including voluntary reduction in food intake, which compromises the supply of energy to the brain. Glial cells, the major population of nerve cells in the central nervous system, play a crucial role in supplying energy to the neurons. The corpus callosum (CC) is the largest white matter tract in mammals, and more than 99% of the cell somata correspond to glial cells in rodents. Whether glial cell density is altered in anorexia is unknown. Thus, the aim of this study was to estimate glial cell density in the three main regions of the CC (genu, body, and splenium) in a murine model of DIA. The astrocyte density was significantly reduced (~34%) for the DIA group in the body of the CC, whereas in the genu and the splenium no significant changes were observed. DIA and forced food restriction (FFR) also reduced the ratio of astrocytes to glial cells by 57.5% and 22%, respectively, in the body of CC. Thus, we conclude that DIA reduces astrocyte density only in the body of the rat CC. PMID:26090235

  15. The development of the corpus callosum in the healthy human brain.

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    Luders, Eileen; Thompson, Paul M; Toga, Arthur W

    2010-08-18

    The corpus callosum changes structurally throughout life, but most dramatically during childhood and adolescence. Even so, existing studies of callosal development tend to use parcellation schemes that may not capture the complex spatial profile of anatomical changes. Thus, more detailed mapping of callosal growth processes is desirable to create a normative reference. This will help to relate and interpret other structural, functional, and behavioral measurements, both from healthy subjects and pediatric patients. We applied computational surface-based mesh-modeling methods to analyze callosal morphology at extremely high spatial resolution. We mapped callosal development and explored sex differences in a large and well matched sample of healthy children and adolescents (n = 190) aged 5-18 years. Except for the rostrum in females, callosal thickness increased across the whole surface, with sex- and region-specific rates of growth, and at times shrinkage. The temporally distinct changes in callosal thickness are likely to be a consequence of varying degrees of axonal myelination, redirection, and pruning. Alternating phases of callosal growth and shrinkage may reflect a permanent adjustment and fine-tuning of fibers connecting homologous cortical areas during childhood and adolescence. Our findings emphasize the importance of taking into account sex differences in future studies, as existing developmental effects might remain disguised (or biased toward the effect of the dominant sex in unbalanced statistical designs) when pooling male and female samples.

  16. The corpus callosum in primates: processing speed of axons and the evolution of hemispheric asymmetry

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    Phillips, Kimberley A.; Stimpson, Cheryl D.; Smaers, Jeroen B.; Raghanti, Mary Ann; Jacobs, Bob; Popratiloff, Anastas; Hof, Patrick R.; Sherwood, Chet C.

    2015-01-01

    Interhemispheric communication may be constrained as brain size increases because of transmission delays in action potentials over the length of axons. Although one might expect larger brains to have progressively thicker axons to compensate, spatial packing is a limiting factor. Axon size distributions within the primate corpus callosum (CC) may provide insights into how these demands affect conduction velocity. We used electron microscopy to explore phylogenetic variation in myelinated axon density and diameter of the CC from 14 different anthropoid primate species, including humans. The majority of axons were less than 1 µm in diameter across all species, indicating that conduction velocity for most interhemispheric communication is relatively constant regardless of brain size. The largest axons within the upper 95th percentile scaled with a progressively higher exponent than the median axons towards the posterior region of the CC. While brain mass among the primates in our analysis varied by 97-fold, estimates of the fastest cross-brain conduction times, as conveyed by axons at the 95th percentile, varied within a relatively narrow range between 3 and 9 ms across species, whereas cross-brain conduction times for the median axon diameters differed more substantially between 11 and 38 ms. Nonetheless, for both size classes of axons, an increase in diameter does not entirely compensate for the delay in interhemispheric transmission time that accompanies larger brain size. Such biophysical constraints on the processing speed of axons conveyed by the CC may play an important role in the evolution of hemispheric asymmetry. PMID:26511047

  17. Transcriptome analysis of amoeboid and ramified microglia isolated from the corpus callosum of rat brain

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    Parakalan Rangarajan

    2012-06-01

    Full Text Available Abstract Background Microglia, the resident immune cells of the central nervous system (CNS, have two distinct phenotypes in the developing brain: amoeboid form, known to be amoeboid microglial cells (AMC and ramified form, known to be ramified microglial cells (RMC. The AMC are characterized by being proliferative, phagocytic and migratory whereas the RMC are quiescent and exhibit a slow turnover rate. The AMC transform into RMC with advancing age, and this transformation is indicative of the gradual shift in the microglial functions. Both AMC and RMC respond to CNS inflammation, and they become hypertrophic when activated by trauma, infection or neurodegenerative stimuli. The molecular mechanisms and functional significance of morphological transformation of microglia during normal development and in disease conditions is not clear. It is hypothesized that AMC and RMC are functionally regulated by a specific set of genes encoding various signaling molecules and transcription factors. Results To address this, we carried out cDNA microarray analysis using lectin-labeled AMC and RMC isolated from frozen tissue sections of the corpus callosum of 5-day and 4-week old rat brain respectively, by laser capture microdissection. The global gene expression profiles of both microglial phenotypes were compared and the differentially expressed genes in AMC and RMC were clustered based on their functional annotations. This genome wide comparative analysis identified genes that are specific to AMC and RMC. Conclusions The novel and specific molecules identified from the trancriptome explains the quiescent state functioning of microglia in its two distinct morphological states.

  18. The development of corpus callosum microstructure and associations with bimanual task performance in healthy adolescents.

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    Muetzel, Ryan L; Collins, Paul F; Mueller, Bryon A; M Schissel, Ann; Lim, Kelvin O; Luciana, Monica

    2008-02-15

    Cross-sectional and longitudinal volumetric studies suggest that the corpus callosum (CC) continues to mature structurally from infancy to adulthood. Diffusion tensor imaging (DTI) provides in vivo information about the directional organization of white matter microstructure and shows potential for elucidating even more subtle brain changes during adolescent development. We used DTI to examine CC microstructure in healthy right-handed adolescents (n=92, ages 9-24 years) and correlated the imaging data with motor task performance. The primary DTI variable was fractional anisotropy (FA), which reflects the degree of white matter's directional organization. Participants completed an alternating finger tapping test to assess interhemispheric transfer and motor speed. Task performance was significantly correlated with age. Analyses of variance indicated that 9- to 11-year-olds generally performed worse than each of the older groups. Males outperformed females. Significant positive correlations between age and FA were observed in the splenium of the CC, which interconnects posterior cortical regions. Analyses of variance indicated that individuals older than 18 years had significantly higher FA than 9- to 11-year-olds. FA levels in the genu and splenium correlated significantly with task performance. Regression analyses indicated that bimanual coordination was significantly predicted by age, gender, and splenium FA. Decreases in alternating finger tapping time and increases in FA likely reflect increased myelination in the CC and more efficient neuronal signal transmission. These findings expand upon existing neuroimaging reports of CC development by showing associations between bimanual coordination and white matter microstructural organization in an adolescent sample.

  19. Properties and fate of oligodendrocyte progenitor cells in the corpus callosum, motor cortex, and piriform cortex of the mouse.

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    Clarke, Laura E; Young, Kaylene M; Hamilton, Nicola B; Li, Huiliang; Richardson, William D; Attwell, David

    2012-06-13

    Oligodendrocyte progenitor cells (OPCs) in the postnatal mouse corpus callosum (CC) and motor cortex (Ctx) reportedly generate only oligodendrocytes (OLs), whereas those in the piriform cortex may also generate neurons. OPCs have also been subdivided based on their expression of voltage-gated ion channels, ability to respond to neuronal activity, and proliferative state. To determine whether OPCs in the piriform cortex have inherently different physiological properties from those in the CC and Ctx, we studied acute brain slices from postnatal transgenic mice in which GFP expression identifies OL lineage cells. We whole-cell patch clamped GFP-expressing (GFP(+)) cells within the CC, Ctx, and anterior piriform cortex (aPC) and used prelabeling with 5-ethynyl-2'-deoxyuridine (EdU) to assess cell proliferation. After recording, slices were immunolabeled and OPCs were defined by strong expression of NG2. NG2(+) OPCs in the white and gray matter proliferated and coexpressed PDGFRα and voltage-gated Na(+) channels (I(Na)). Approximately 70% of OPCs were capable of generating regenerative depolarizations. In addition to OLIG2(+) NG2(+) I(Na)(+) OPCs and OLIG2(+) NG2(neg) I(Na)(neg) OLs, we identified cells with low levels of NG2 limited to the soma or the base of some processes. These cells had a significantly reduced I(Na) and a reduced ability to incorporate EdU when compared with OPCs and probably correspond to early differentiating OLs. By combining EdU labeling and lineage tracing using Pdgfrα-CreER(T2) : R26R-YFP transgenic mice, we double labeled OPCs and traced their fate in the postnatal brain. These OPCs generated OLs but did not generate neurons in the aPC or elsewhere at any time that we examined.

  20. Developmental malformation of the corpus callosum: a review of typical callosal development and examples of developmental disorders with callosal involvement.

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    Paul, Lynn K

    2011-03-01

    This review provides an overview of the involvement of the corpus callosum (CC) in a variety of developmental disorders that are currently defined exclusively by genetics, developmental insult, and/or behavior. I begin with a general review of CC development, connectivity, and function, followed by discussion of the research methods typically utilized to study the callosum. The bulk of the review concentrates on specific developmental disorders, beginning with agenesis of the corpus callosum (AgCC)-the only condition diagnosed exclusively by callosal anatomy. This is followed by a review of several genetic disorders that commonly result in social impairments and/or psychopathology similar to AgCC (neurofibromatosis-1, Turner syndrome, 22q11.2 deletion syndrome, Williams yndrome, and fragile X) and two forms of prenatal injury (premature birth, fetal alcohol syndrome) known to impact callosal development. Finally, I examine callosal involvement in several common developmental disorders defined exclusively by behavioral patterns (developmental language delay, dyslexia, attention-deficit hyperactive disorder, autism spectrum disorders, and Tourette syndrome).

  1. Early anisotropy changes in the corpus callosum of patients with optic neuritis

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    Bester, M.; Ding, X.Q.; Holst, B.; Fiehler, J. [University Medical Center Hamburg-Eppendorf, Department of Neuroradiology, Hamburg (Germany); Heesen, C.; Schippling, S.; Martin, R. [University Medical Center Hamburg-Eppendorf, Department of Neuroradiology, Hamburg (Germany); University Medical Center Hamburg-Eppendorf, Institute for Neuroimmunology and Clinical MS Research, Hamburg (Germany)

    2008-07-15

    Optic neuritis (ON) and any other early manifestation of multiple sclerosis (MS) are referred to as clinically isolated syndrome (CIS) as long as MS is suspected. In this prospective study we aimed to determine whether diffusion tensor imaging (DTI) could quantify structural changes in patients with early MS. A total of 24 patients and 15 control subjects were prospectively followed by clinical examinations and MRI. the main inclusion criterion was presentation with ON. Patients underwent serial MRI scans: MRI1 (baseline, n=24), MRI2 (mean 6.6 months, n=24), MRI3 (mean 13.0 months, n=14), MRI4 (mean 39.4 months, n=5). Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps were derived from DTI. Four regions of interest (ROIs) were defined in normal-appearing white matter (NAWM). In the temporal course FA decreased in the genu of the callosal body (GCC) from MRI1 to MRI4 (P=0.005) and in the splenium of the callosal body (SCC) (P=0.006). Patients already had lower FA values in the SCC (P<0.01) on MRI1 compared with the controls. Patients had lower FA values in the GCC (P<0.01) starting from MRI2. Patients with definite MS on follow-up (n=9) showed a correlation between FA in the SCC and time (r=-0.40, P=0.004), whereas patients without progression did not. Our findings suggest that the corpus callosum is an early site for development of anisotropy changes in MS patients with ON. There seems to be a primary FA decrease in all patients with ON that only deteriorates in the group developing definite MS. (orig.)

  2. Effect of registration on corpus callosum population differences found with DBM analysis

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    Han, Zhaoying; Thornton-Wells, Tricia A.; Gore, John C.; Dawant, Benoit M.

    2011-03-01

    Deformation Based Morphometry (DBM) is a relatively new method used for characterizing anatomical differences among populations. DBM is based on the analysis of the deformation fields generated by non-rigid registration algorithms, which warp the individual volumes to one standard coordinate system. Although several studies have compared non-rigid registration algorithms for segmentation tasks, few studies have compared the effect of the registration algorithm on population differences that may be uncovered through DBM. In this study, we compared DBM results obtained with five well established non-rigid registration algorithms on the corpus callosum (CC) in thirteen subjects with Williams Syndrome (WS) and thirteen Normal Control (NC) subjects. The five non-rigid registration algorithms include: (1) The Adaptive Basis Algorithm (ABA); (2) Image Registration Toolkit (IRTK); (3) FSL Nonlinear Image Registration Tool (FSL); (4) Automatic Registration Tools (ART); and (5) the normalization algorithm available in SPM8. For each algorithm, the 3D deformation fields from all subjects to the atlas were obtained and used to calculate the Jacobian determinant (JAC) at each voxel in the mid-sagittal slice of the CC. The mean JAC maps for each group were compared quantitatively across different nonrigid registration algorithms. An ANOVA test performed on the means of the JAC over the Genu and the Splenium ROIs shows the JAC differences between nonrigid registration algorithms are statistically significant over the Genu for both groups and over the Splenium for the NC group. These results suggest that it is important to consider the effect of registration when using DBM to compute morphological differences in populations.

  3. Progesterone Enhanced Remyelination in the Mouse Corpus Callosum After Cuprizone Induced Demyelination

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    Iraj Ragerdi Kashani

    2015-11-01

    Full Text Available Background: Progesterone as a sex steroid hormone is thought to affect and prevent demyelination, but its role in promoting myelin repair is far less investigated. In this study, remyelinating potential of progesterone in corpus callosum was evaluated on an experimental model of MS. Methods: In this experimental study, adult male C57BL/6 mice were fed with 0.2% (w/w cuprizone in ground breeder chow ad libitum for 6 weeks. At day zero, after cuprizone removal, mice were divided randomly into two groups: (a placebo group, which received saline pellet implant, (b progesterone group, which received progesterone pellet implant. Some mice of the same age were fed with their normal diet to serve as the healthy control group. Two weeks after progesterone administration, Myelin content was assessed by Luxol-fast blue staining. The myelin basic protein (MBP and proteolipid protein (PLP expression were assessed using Western blot analysis and the changes in the number of oligodendrocytes and oligodendroglial progenitor cells were assessed by immunohistochemistry (IHC and flow cytometry. Results: Luxol-fast blue staining revealed enhanced remyelination in the progesterone group when compared with the placebo group. Densitometry measurements of immunoblots demonstrated that MBP and PLP proteins contents were significantly increased in the progesterone group compared with the placebo group. Flow cytometry and IHC analysis showed increases in Olig2 and O4 cells in the progesterone group compared with the placebo group. Conclusion: Overall, our results indicate that progesterone treatment can stimulate myelin production and that it may provide a feasible and practical way for remyelination in diseases such as multiple sclerosis.

  4. MRI in callosal apraxia and agraphia due to a traumatic lesion in the posterior trunk of the corpus callosum

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    Yasumura, Shuichi; Ito, Naoki; Terunuma, Hiroshi; Matsuzaki, Takayuki; Iwabuchi, Reiko

    1987-08-01

    We discussed functional topography of the corpus callosum in a case with ideo-motor apraxia and agraphia of the left hand due to a traumatic callosal hematoma confirmed by MRI. The patient was a 35-year-old right-handed woman with head injury in a traffic accident. On admission she was semi-comatose with left oculomotor palsy and her left upper limb showed a decorticate rigidity by noxious stimuli, however, she became alert within 14 days. X-ray CT showed an abnormal high density area in the posterior part of the trunk of the corpus callosum on admission. MRI (inversion recovery technique) on the 60th hospital day showed a low intensity area extending for about 2 cm posteriorly from the center of the trunk. Sequential neuropsychological examinations for the callosal disconnection syndrome were performed. The patient showed ideo-motor apraxia and agraphia in her left hand only. Her response to verbal commands were all parapraxic except for correct use of a comb and a tooth brush. Her writings with her left hand were those of scrawls due to apraxia. These apraxia and agraphia of the left hand were transient and recovered completely within 80 days of onset. Transient impairement of bimanual coordination movement was also observed. Ataxie optique, callosal pseudoneglect, left hand tactile anomia, difficulty of somesthetic transfer or diagonistic dyspraxia was not observed. Based on the neuropsychological and the MRI findings we suggest that the lesion in the posterior part of the trunk of the corpus callosum is important for causing ideo-motor apraxia and agraphia of the left hand.

  5. Histological correlation of diffusional kurtosis and white matter modeling metrics in cuprizone-induced corpus callosum demyelination.

    Science.gov (United States)

    Falangola, Maria F; Guilfoyle, David N; Tabesh, Ali; Hui, Edward S; Nie, Xingju; Jensen, Jens H; Gerum, Scott V; Hu, Caixia; LaFrancois, John; Collins, Heather R; Helpern, Joseph A

    2014-08-01

    The cuprizone mouse model is well established for studying the processes of both demyelination and remyelination in the corpus callosum, and it has been utilized together with diffusion tensor imaging (DTI) to investigate myelin and axonal pathology. Although some underlying morphological mechanisms contributing to the changes in diffusion tensor (DT) metrics have been identified, the understanding of specific associations between histology and diffusion measures remains limited. Diffusional kurtosis imaging (DKI) is an extension of DTI that provides metrics of diffusional non-Gaussianity, for which an associated white matter modeling (WMM) method has been developed. The main goal of the present study was to quantitatively assess the relationships between diffusion measures and histological measures in the mouse model of cuprizone-induced corpus callosum demyelination. The diffusional kurtosis (DK) and WMM metrics were found to provide additional information that enhances the sensitivity to detect the morphological heterogeneity in the chronic phase of the disease process in the rostral segment of the corpus callosum. Specifically, in the rostral segment, axonal water fraction (d = 2.6; p < 0.0001), radial kurtosis (d = 2.0; p = 0.001) and mean kurtosis (d = 1.5; p = 0.005) showed the most sensitivity between groups with respect to yielding statistically significant p values and high Cohen's d values. These results demonstrate the ability of DK and WMM metrics to detect white mater changes and inflammatory processes associated with cuprizone-induced demyelination. They also validate, in part, the application of these new WMM metrics for studying neurological diseases, as well as helping to elucidate their biophysical meaning.

  6. 胼胝体梗死:临床与影像学特征%Corpus callosum infarction: clinical and imaging features

    Institute of Scientific and Technical Information of China (English)

    盛蕾; 胡丹; 肖婧; 张兰坤; 胡君; 王立; 李传游; 丁彩霞; 江雪梅

    2013-01-01

    Objeetive To investigate the clinical and imaging features in patients with corpus callosum infarction.Methods The patients with corpus callosum infarction confirmed by MRI were collected retrospectively.Their clinical manifestations and imaging data were analyzed.Results The corpus callosum infarction accounted for 1.04% of all patients with cerebral infarction.Its major risk factors were hypertension,coronary heart disease,and diabetes.Its typical clinical manifestations included ideomotor apraxia (42.9%),frontal gait (28.6%) and alien hand syndrome (14.3%) accompanied with limb paralysis,disturbance of consciousness,cognitive impairment and other symptoms.MRI detected 8 corpus callosum lesions.Most were involved in the body of corpus callosum (62.5%),followed by splenium (25.0%) and genu (1/8,12.5%).The frontal lobe (57.1%),basal ganglia (42.9%) and occipital lobe (42.9%) were frequently involved.Diffusion tensor imaging revealed that the fiber connections of the body and genu of corpus callosum were broken in one case.Angiography showed that 6 patients had vascular stenosis or occlusion,and the most common was vertebral artery stenosis (66.7%),followed by anterior cerebral artery (50.0%),and common carotid arery,internal carotid artery and middle cerebral artery stenoses were rare (all 33.3%).Conclusions The incidence of corpus callosum infarction is low.Atherosclerosis is the pathogenic key.Its clinical manifestations are diverse,and they are associated with the sites of infarction.%目的 探讨胼胝体梗死患者的临床和影像学特征.方法 回顾性收集经颅脑MRI证实的胼胝体梗死患者,对其临床表现和影像学资料进行分析.结果 胼胝体梗死占所有脑梗死患者的1.04%(7/671),其主要危险因素是高血压、冠心病和糖尿病.典型表现包括观念运动性失用(42.9%)、额叶步态(28.6%)和异己手综合征(14.3%),可伴有肢体瘫痪、意识障碍和认知损害等

  7. Human amniotic epithelial cells express specific markers of nerve cells and migrate along the nerve fibers in the corpus callosum

    Institute of Scientific and Technical Information of China (English)

    Zhiyuan Wu; Guozhen Hui; Yi Lu; Tianjin Liu; Qin Huang; Lihe Guo

    2012-01-01

    Human amniotic epithelial cells were isolated from a piece of fresh amnion. Using immunocytochemical methods, we investigated the expression of neuronal phenotypes (microtubule-associated protein-2, glial fibrillary acidic protein and nestin) in human amniotic epithelial cells. The conditioned medium of human amniotic epithelial cells promoted the growth and proliferation of rat glial cells cultured in vitro, and this effect was dose-dependent. Human amniotic epithelial cells were further transplanted into the corpus striatum of healthy adult rats and the grafted cells could integrate with the host and migrate 1-2 mm along the nerve fibers in corpus callosum. Our experimental findings indicate that human amniotic epithelial cells may be a new kind of seed cells for use in neurograft.

  8. A semi-automated method for measuring thickness and white matter integrity of the corpus callosum

    Directory of Open Access Journals (Sweden)

    S Andronikou

    2012-12-01

    Full Text Available Aim. Diseases affecting cerebral white matter may lead to left-right asymmetries and atrophy of interhemispheric connections, i.e. the corpus callosum (CC. Our aim was to describe and test a semi-automated system that divides the midline CC into a number of segments and determines thickness at each, then performs fibre tracking from these segments. Methods. Six normal female volunteers (average age 25.8 ±6.7 years and a female patient with diagnosed multiple sclerosis (age 26 years were scanned on a 3T MRI. We performed diffusion-weighted imaging in 12 directions, and calculated diffusion tensors and fractional anisotropy (FA maps from this pre-processed data. Fibre tracking from a region-of-interest encompassing the entire CC was done. This fibre data, together with FA maps and the unweighted diffusion tensor imaging (DTI image (b = 0 s/mm2, were imported into a custom tool written in MATLAB. The midline sagittal position was carefully defined by selecting multiple midline points in coronal and axial views and rotating the image volume and fibre co-ordinates accordingly. Using the customised tool, dorsal and ventral CC contours were manually drawn on the mid-sagittal FA image, initiating automated calculation of a contour midway between these manually drawn lines. The programme was designed to then divide the midline contour into a pre-selected number of segments; from each segment border, perpendicular spokes were projected until they intersected with the dorsal and ventral contours. This technique divided the CC into a pre-set amount of segments, the number of which was limited by the spatial resolution. It was decided to set the number at 40 to ensure that each segment depicted a contiguous strip of voxels across the CC from the dorsal to the ventral contour. The system allows these segments to then be used as seeds for separate fibre tracking in each cerebral hemisphere, and various parameters are automatically plotted as a function of

  9. 胼胝体梗死的临床与影像学分析%Clinical and imaging analysis of corpus callosum infarction

    Institute of Scientific and Technical Information of China (English)

    李新辉; 王玉洁; 白璇; 辛岳

    2011-01-01

    Objective To investigate the clinical and imaging characteristics in patients with corpus callosum infarction.Methods The clinical data of 416 patients meetingthe diagnosis of cerebral infarction Were collected,in which,8 patients Were confirmed as corpus callosum infarction by MRI.Results Corpus callosum infarction accounted for 1.9% of all patients with cerebral infarction.CT scan did not show the corpus callosum infaretiom in 7 patients.The nonenhanced MRI revealed the lesions.The enhanced MRI revealed the lesion in another patient.The infarction foci were not only involved in the corpus callosum(knee,body or splenium),but also cornplicated with frontal lobe,occipital lobe and thalamus infractions.The clinical manifesta tions of the corpus callosum infarction were different due to the specific lesion sites.The simple infarction in the body of the corpus callosum mainly presented as contralateral paraparesis.atria,and left limb apra.xia;the infarction in the knee of the corpus callosum mainly presented as lower limb paralysis or contralateral paraparesis;the infarction in the splenium of the corpus callosum presented as limb paralysis and dizziness;the lacunar infarct in the corpus callosum had no obvious clinical manifestations.The patients who complicated with frontal lobe and thalamus infarction had behavioral and psychological syrnptonm,including mental retardation,language abnormalities.and incontinence.Conelusions Corpus callosum infarction is not common.MRI is the basis of diagaosis.The clinical manifestation is lack of specificity.and it is agsociated with the location of corpus callosum infarction and whether it comolicates with the infarction on other part.%目的 探讨胼胝体梗死患者的临床和影像学特点.方法 收集符合脑梗死诊断的416例患者的临床资料,其中8例经过MRI证实为胼胝体梗死.结果 胼胝体梗死占全部脑梗死患者的1.9%.7例CT扫描未显示胼胝体梗死,经非增强MRI检查显示病灶,另1

  10. A T1 and DTI fused 3D corpus callosum analysis in pre- vs. post-season contact sports players

    Science.gov (United States)

    Lao, Yi; Law, Meng; Shi, Jie; Gajawelli, Niharika; Haas, Lauren; Wang, Yalin; Leporé, Natasha

    2015-01-01

    Sports related traumatic brain injury (TBI) is a worldwide public health issue, and damage to the corpus callosum (CC) has been considered as an important indicator of TBI. However, contact sports players suffer repeated hits to the head during the course of a season even in the absence of diagnosed concussion, and less is known about their effect on callosal anatomy. In addition, T1-weighted and diffusion tensor brain magnetic resonance images (DTI) have been analyzed separately, but a joint analysis of both types of data may increase statistical power and give a more complete understanding of anatomical correlates of subclinical concussions in these athletes. Here, for the first time, we fuse T1 surface-based morphometry and a new DTI analysis on 3D surface representations of the CCs into a single statistical analysis on these subjects. Our new combined method successfully increases detection power in detecting differences between pre- vs. post-season contact sports players. Alterations are found in the ventral genu, isthmus, and splenium of CC. Our findings may inform future health assessments in contact sports players. The new method here is also the first truly multimodal diffusion and T1-weighted analysis of the CC, and may be useful to detect anatomical changes in the corpus callosum in other multimodal datasets.

  11. Cerebral metabolic and structural alterations in hereditary spastic paraplegia with thin corpus callosum assessed by MRS and DTI

    Energy Technology Data Exchange (ETDEWEB)

    Dreha-Kulaczewski, Steffi [Georg August University, Department of Pediatrics and Pediatric Neurology, Faculty of Medicine, Goettingen (Germany); Georg August University, MR Research in Neurology and Psychiatry, Goettingen (Germany); Dechent, Peter; Helms, Gunther [Georg August University, MR Research in Neurology and Psychiatry, Goettingen (Germany); Frahm, Jens [Biomedizinische NMR Forschungs GmbH, Max-Planck-Institut fuer Biophysikalische Chemie, Goettingen (Germany); Gaertner, Jutta; Brockmann, Knut [Georg August University, Department of Pediatrics and Pediatric Neurology, Faculty of Medicine, Goettingen (Germany)

    2006-12-15

    Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is a complicated form of autosomal-recessive hereditary spastic paraplegia. Characteristic clinical features comprise progressive spastic gait, cognitive impairment, and ataxia. Diagnostic MRI findings include thinning of the corpus callosum and non-progressive white matter (WM) alterations. To study the extent of axonal involvement, we performed localized proton magnetic resonance spectroscopy (MRS) of the cerebral WM and cortical grey matter (GM) in a patient with HSP-TCC at 20 and 25 years of age. The second investigation included diffusion tensor imaging (DTI). While MRS of the GM was normal, affected WM was characterized by major metabolic alterations such as reduced concentrations of N-acetylaspartate and N-acetylaspartyl-glutamate, creatine and phosphocreatine, and choline-containing compounds as well as elevated levels of myo-inositol. These abnormalities showed progression over a period of 5 years. DTI revealed increased mean diffusivity as well as reduced fractional anisotropy in periventricular WM. The metabolic and structural findings are consistent with progressive neuroaxonal loss in the WM accompanied by astrocytic proliferation - histopathological changes known to occur in HSP-TCC. Our results are in agreement with the hypothesis that the primary pathological process in HSP-TCC affects the axon, possibly due to impaired axonal trafficking. (orig.)

  12. Connectivity and the corpus callosum in autism spectrum conditions: insights from comparison of autism and callosal agenesis.

    Science.gov (United States)

    Booth, Rhonda; Wallace, Gregory L; Happé, Francesca

    2011-01-01

    Neural models of autism spectrum disorders (ASDs) have moved, in recent years, from a lesion model to a focus on abnormal connectivity. In this chapter, we review this work and summarize findings from our recent research comparing autism and agenesis of the corpus callosum (AgCC). We discuss our findings in the context of the "fractionable triad" account and highlight three main points. First, the social aspects of autism can be found in isolation, not accompanied by the nonsocial features of this disorder, supporting a view of autism as a "compound," rather than "monolithic," condition. Second, many young people with callosal agenesis show theory of mind- and emotion-processing deficits akin to those seen in autism. Diagnostic overshadowing may mean these people do not receive interventions that have proven beneficial in ASD. Last, study of AgCC shows that it is possible, in some cases, to develop good social cognitive skills in the absence of the corpus callosum, presenting a challenge to future connectivity models of autism.

  13. Low-cost, rapidly-developed, 3D printed in vitro corpus callosum model for mucopolysaccharidosis type I

    Science.gov (United States)

    Tabet, Anthony; Gardner, Matthew; Swanson, Sebastian; Crump, Sydney; McMeekin, Austin; Gong, Diana; Tabet, Rebecca; Hacker, Benjamin; Nestrasil, Igor

    2017-01-01

    The rising prevalence of high throughput screening and the general inability of (1) two dimensional (2D) cell culture and (2) in vitro release studies to predict in vivo neurobiological and pharmacokinetic responses in humans has led to greater interest in more realistic three dimensional (3D) benchtop platforms. Advantages of 3D human cell culture over its 2D analogue, or even animal models, include taking the effects of microgeometry and long-range topological features into consideration. In the era of personalized medicine, it has become increasingly valuable to screen candidate molecules and synergistic therapeutics at a patient-specific level, in particular for diseases that manifest in highly variable ways. The lack of established standards and the relatively arbitrary choice of probing conditions has limited in vitro drug release to a largely qualitative assessment as opposed to a predictive, quantitative measure of pharmacokinetics and pharmacodynamics in tissue. Here we report the methods used in the rapid, low-cost development of a 3D model of a mucopolysaccharidosis type I patient’s corpus callosum, which may be used for cell culture and drug release. The CAD model is developed from in vivo brain MRI tracing of the corpus callosum using open-source software, printed with poly (lactic-acid) on a Makerbot Replicator 5X, UV-sterilized, and coated with poly (lysine) for cellular adhesion. Adaptations of material and 3D printer for expanded applications are also discussed. PMID:28357042

  14. Novel missense mutation in the L1 gene in a child with corpus callosum agenesis, retardation, adducted thumbs, spastic paraparesis, and hydrocephalus

    NARCIS (Netherlands)

    Sztriha, L; Frossard, P; Hofstra, RMW; Verlind, E; Nork, M

    2000-01-01

    Corpus callosum agenesis, retardation, adducted thumbs, spastic paraparesis, and hydrocephalus (CRASH syndrome) is an X-linked recessive disorder caused by mutations in the neuronal cell adhesion molecule L1 (L1CAM) gene. L1 plays a key role in axon outgrowth and pathfinding during the development o

  15. Lipoma del cuerpo calloso con crisis convulsiva que ocasiona broncoaspiración alimentaria mortal Lipoma of the corpus callosum with seizure which causes fatal alimentary aspiration

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    J. Lucena

    2004-07-01

    Full Text Available Los lipomas del cuerpo calloso representan hasta el 5% de las malformaciones, tumorales o no, del cuerpo calloso. Actualmente son considerados malformaciones congénitas en lugar de verdaderas neoplasias. La mayoría son sintomáticos, pero algunos se asocian a síntomas neurológicos inespecíficos como retraso psicomotor, cefalea, epilepsia y parálisis cerebral. Se expone el caso de un varón de 42 años que fallece por broncoaspiración alimentaria secundaria a crisis convulsiva. El estudio neuropatológico puso de manifiesto dos lipomas situados en la rodilla del cuerpo calloso. Se destaca la necesidad de realizar tratamiento antiepiléptico en los lipomas del cuerpo calloso que se manifiestan clínicamente en forma de crisis comiciales.Lipomas of the corpus callosum make up approximately 5% of the tumours of the corpus callosum. Nowadays, they are considered congenital malformations rather than true neoplasms. They are usually asymptomatic; however they are sometimes associated with unspecific neurological symptoms such as psychomotor retardation, headache, epilepsy and cerebral palsy. A case is presented of a 42-year-old man who died due to alimentary aspiration following a seizure. Neuropathological study showed two lipomas located in the splenium of the corpus callosum. Also, we emphasise the importance of the anti-epileptic treatment in the corpus callosum lipomas which are associated with epilepsy.

  16. Conduct disorder in females is associated with reduced corpus callosum structural integrity independent of comorbid disorders and exposure to maltreatment.

    Science.gov (United States)

    Lindner, P; Savic, I; Sitnikov, R; Budhiraja, M; Liu, Y; Jokinen, J; Tiihonen, J; Hodgins, S

    2016-01-19

    The behavioral phenotype and genotype of conduct disorder (CD) differ in males and females. Abnormalities of white matter integrity have been reported among males with CD and antisocial personality disorder (ASPD). Little is known about white matter integrity in females with CD. The present study aimed to determine whether abnormalities of white matter are present among young women who presented CD before the age of 15, and whether abnormalities are independent of the multiple comorbid disorders and experiences of maltreatment characterizing females with CD that may each in themselves be associated with alterations of the white matter. Three groups of women, aged on average 24 years, were scanned using diffusion tensor imaging and compared: 28 with prior CD, three of whom presented ASPD; a clinical comparison (CC) group of 15 women with no history of CD but with similar proportions who presented alcohol dependence, drug dependence, anxiety disorders, depression disorders and physical and sexual abuse as the CD group; and 24 healthy women. Whole-brain, tract-based spatial statistics were computed to investigate differences in fractional anisotropy, axial diffusivity and radial diffusivity. Compared with healthy women, women with prior CD showed widespread reductions in axial diffusivity primarily in frontotemporal regions. After statistically adjusting for comorbid disorders and maltreatment, group differences in the corpus callosum body and genu (including forceps minor) remained significant. Compared with the CC group, women with CD showed reduced fractional anisotropy in the body and genu of the corpus callosum. No differences were detected between the CD and healthy women in the uncinate fasciculus.

  17. Ultrasound measurement of the corpus callosum and neural development of premature infants*

    Institute of Scientific and Technical Information of China (English)

    Fang Liu; Shikao Cao; Jiaoran Liu; Zhifang Du; Zhimei Guo; Changjun Ren

    2013-01-01

    Length and thickness of 152 corpus cal osa were measured in neonates within 24 hours of birth. Using ultrasonic diagnostic equipment with a neonatal brain-specific probe, corpus cal osum length and thickness of the genu, body, and splenium were measured on the standard mid-sagittal plane, and the anteroposterior diameter of the genu was measured in the coronal plane. Results showed that corpus cal osum length as wel as thickness of the genu and splenium increased with gesta-tional age and birth weight, while other measures did not. These three factors on the standard mid-sagittal plane are therefore likely to be suitable for real-time evaluation of corpus cal osum de-velopment in premature infants using cranial ultrasound. Further analysis revealed that thickness of the body and splenium and the anteroposterior diameter of the genu were greater in male infants than in female infants, suggesting that there are sex differences in corpus cal osum size during the neonatal period. A second set of measurements were taken from 40 premature infants whose ges-tational age was 34 weeks or less. Corpus cal osum measurements were corrected to a gestational age of 40 weeks, and infants were grouped for analysis depending on the outcome of a neonatal behavioral neurological assessment. Compared with infants with a normal neurological assessment, corpus cal osum length and genu and splenium thicknesses were less in those with abnormalities, indicating that corpus cal osum growth in premature infants is associated with neurobehavioral de-velopment during the early extrauterine stage.

  18. Sex-related difference in human white matter volumes studied: Inspection of the corpus callosum and other white matter by VBM

    Science.gov (United States)

    Shiino, Akihiko; Chen, Yen-Wei; Tanigaki, Kenji; Yamada, Atsushi; Vigers, Piers; Watanabe, Toshiyuki; Tooyama, Ikuo; Akiguchi, Ichiro

    2017-01-01

    It has been contended that any observed difference of the corpus callosum (CC) size between men and women is not sex-related but brain-size-related. A recent report, however, showed that the midsagittal CC area was significantly larger in women in 37 brain-size-matched pairs of normal young adults. Since this constituted strong evidence of sexual dimorphism and was obtained from publicly available data in OASIS, we examined volume differences within the CC and in other white matter using voxel-based morphometry (VBM). We created a three-dimensional region of interest of the CC and measured its volume. The VBM statistics were analyzed by permutation test and threshold-free cluster enhancement (TFCE) with the significance levels at FWER sex-related difference. We also found that white matter in the bilateral anterior frontal regions and the left lateral white matter near to Broca’s area were larger in women, whereas there were no significant larger regions in men. Since we used brain-size-matched subjects, our results gave strong volumetric evidence of localized sexual dimorphism of white matter.

  19. Fetal development of the corpus callosum: Insights from a 3T DTI and tractography study in a patient with segmental callosal agenesis.

    Science.gov (United States)

    Scola, Elisa; Sirgiovanni, Ida; Avignone, Sabrina; Cinnante, Claudia Maria; Biffi, Riccardo; Fumagalli, Monica; Triulzi, Fabio

    2016-10-01

    Commissural embryology mechanisms are not yet completely understood. The study and comprehension of callosal dysgenesis can provide remarkable insights into embryonic or fetal commissural development. The diffusion tensor imaging (DTI) technique allows the in vivo analyses of the white-matter microstructure and is a valid tool to clarify the disturbances of brain connections in patients with dysgenesis of the corpus callosum (CC). The segmental callosal agenesis (SCAG) is a rare partial agenesis of the corpus callosum (ACC). In a newborn with SCAG the DTI and tractography analyses proved that the CC was made of two separate segments consisting respectively of the ventral part in the genu and body of the CC, connecting the frontal lobes, and the dorsal part in the CC splenium and the attached hippocampal commissure (HC), connecting the parietal lobes and the fornix. These findings support the embryological thesis of a separated origin of the ventral and the dorsal parts of the CC.

  20. Why size matters: differences in brain volume account for apparent sex differences in callosal anatomy: the sexual dimorphism of the corpus callosum.

    Science.gov (United States)

    Luders, Eileen; Toga, Arthur W; Thompson, Paul M

    2014-01-01

    Numerous studies have demonstrated a sexual dimorphism of the human corpus callosum. However, the question remains if sex differences in brain size, which typically is larger in men than in women, or biological sex per se account for the apparent sex differences in callosal morphology. Comparing callosal dimensions between men and women matched for overall brain size may clarify the true contribution of biological sex, as any observed group difference should indicate pure sex effects. We thus examined callosal morphology in 24 male and 24 female brains carefully matched for overall size. In addition, we selected 24 extremely large male brains and 24 extremely small female brains to explore if observed sex effects might vary depending on the degree to which male and female groups differed in brain size. Using the individual T1-weighted brain images (n=96), we delineated the corpus callosum at midline and applied a well-validated surface-based mesh-modeling approach to compare callosal thickness at 100 equidistant points between groups determined by brain size and sex. The corpus callosum was always thicker in men than in women. However, this callosal sex difference was strongly determined by the cerebral sex difference overall. That is, the larger the discrepancy in brain size between men and women, the more pronounced the sex difference in callosal thickness, with hardly any callosal differences remaining between brain-size matched men and women. Altogether, these findings suggest that individual differences in brain size account for apparent sex differences in the anatomy of the corpus callosum.

  1. Instrument specific use-dependent plasticity shapes the anatomical properties of the corpus callosum: A comparison between musicians and non-musicians

    Directory of Open Access Journals (Sweden)

    Henning eVollmann

    2014-07-01

    Full Text Available Long-term musical expertise has been shown to be associated with a number of functional and structural brain changes, making it an attractive model for investigating use-dependent plasticity in humans. Physiological interhemispheric inhibition (IHI as examined by transcranial magnetic stimulation has been shown to be correlated with anatomical properties of the corpus callosum as indexed by fractional anisotropy (FA. However, whether or not IHI or the relationship between IHI and FA in the corpus callosum can be modified by different musical training regimes remains largely unknown. We investigated this question in musicians with different requirements for bimanual finger movements (piano and string players and non-expert controls. IHI values were generally higher in musicians, but differed significantly from non-musicians only in string players. IHI was correlated with FA in the posterior midbody of the corpus callosum across all participants. Interestingly, subsequent analyses revealed that this relationship may indeed be modulated by different musical training regimes. Crucially, while string players had greater IHI than non-musicians and showed a positive structure-function relationship, the amount of IHI in pianists was comparable to that of non-musicians and there was no significant structure-function relationship. Our findings indicate instrument specific use-dependent plasticity in both functional (IHI and structural (FA connectivity of motor related brain regions in musicians.

  2. "Multicystic dysplastic kidney (Potter type II syndrome) and agenesis of corpus callosum (ACC) in two consecutive pregnancies: a possible teratogenic effect of electromagnetic exposure in utero".

    Science.gov (United States)

    Tonni, Gabriele; Azzoni, Daniela; Ventura, Alessandro; Ambrosetti, Fabrizio; De Felice, Claudio

    2008-01-01

    Agenesis of the corpus callosum is found in about 5 per 1,000 births and it is due to maldevelopment or, secondary, to destructive lesions. Multicystic dysplastic kidneys is a consequence of either developmental failure of the mesonephric blastema to form nephrons or to early urinary obstruction due to urethral or ureteric atresia and can be found in about 1 per 1,000 live births. A case of fetal multicystic dysplastic kidney disease (Potter type II syndrome) and complete agenesis of the corpus callosum demonstrated by the presence of Probst bundles associated with colpocephaly occurring in the same mother in her two consecutive pregnancies is reported. Data regarding possible teratogenetic effect due to electromagnetic exposure in utero have also been investigated and raised suspicionus as a potential risk factor. In cases of suspected second trimester ultrasound diagnosis of agenesis of corpus callosum (ACC), the following clinical management should be recommended: fetal karyotype; a second level scan with differentiation between underlying conditions such as hydrocephalus and holoprosencephaly; antenatal MRI to enhance the diagnostic accuracy of possible associated neuronal migration (when possible); and direct demonstration of the presence of the Probst bundles to neurohistology.

  3. Acute effects of neonatal dexamethasone treatment on proliferation and astrocyte immunoreactivity in hippocampus and corpus callosum: towards a rescue strategy.

    Science.gov (United States)

    Claessens, Sanne E F; Belanoff, Joseph K; Kanatsou, Sofia; Lucassen, Paul J; Champagne, Danielle L; de Kloet, E Ronald

    2012-10-30

    Dexamethasone (DEX), a synthetic glucocorticoid, has been used to treat respiratory distress syndrome in prematurely born infants. Despite the important short-term benefit on lung function, there is growing concern about the long-term outcome of this treatment, since follow-up studies of prematurely born infants have shown lasting adverse neurodevelopmental effects. Since the mechanism underlying these neurodevelopmental impairments is largely unknown, the aim of the present study was (i) to investigate the acute effects of neonatal DEX treatment on the developing brain; and (ii) to block specifically the effects of DEX on the brain by central administration of the glucocorticoid receptor (GR) antagonist mifepristone. Long Evans rat pups were injected subcutaneously with tapering doses of DEX or saline (SAL) on postnatal days (pnd) 1, 2 and 3. Separate groups received intracerebroventricular injections with mifepristone prior to DEX treatment. On pnd 4 and 10, pups were sacrificed and brains collected for analysis of cell proliferation (Ki-67) and astrogliosis (GFAP). We report that neonatal DEX treatment reduced hippocampal cell proliferation on pnd 4, an effect that was normalized by pnd 10. Although on pnd 4, GFAP expression was not affected, DEX treatment caused a significant reduction in the number and density of astrocytes in hippocampus and corpus callosum on pnd 10, which was normalized by mifepristone pre-treatment. These acute alterations in the neonate brain might underlie later functional impairments reported in DEX-treated animals and humans and further illustrate the impact of early GR activation on brain development.

  4. Reduced corpus-callosum volume in posttraumatic stress disorder highlights the importance of interhemispheric connectivity for associative memory.

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    Saar-Ashkenazy, Rotem; Cohen, Jonathan E; Guez, Jonathan; Gasho, Chris; Shelef, Ilan; Friedman, Alon; Shalev, Hadar

    2014-02-01

    Memory deficits are a common complaint of patients with posttraumatic stress disorder (PTSD). Despite vivid trauma-related memory, previous studies report memory impairment for nontrauma-related stimuli when compared to controls, specifically in associative memory (Guez et al., 2011). Healthy individuals show hemispheric memory asymmetry with left-prefrontal lateralization of encoding and right-prefrontal lateralization of episodic retrieval, suggesting a role for interhemispheric communication in memory-related tasks (Gazzaniga, ; Ringo, Doty, Demeter, & Simard, ). Because brain magnetic resonance imaging (bMRI) studies in PTSD patients report volume changes in various regions, including white matter and corpus callosum (CC), we aimed to test the relationship between memory deficits and CC volume in PTSD patients. We probed for specific alterations in associative memory in PTSD and measured the volume of subportions within the CC employing bMRI. Our main finding was a reduction in CC white-matter volume in PTSD patients, as compared to controls, t(35) = -2.7, p = .010, that was correlated with lower associative performance (r = .76, p = .003). We propose that CC volume reduction is a substrate for the associative memory deficits found in PTSD.

  5. Osseous oral hyaline ring granuloma mimicking a mandible tumor in a child with congenital agenesis of the corpus callosum

    Science.gov (United States)

    Neves-Silva, Rodrigo; Ferreira-Gomes, Camilla-Borges; Palmier, Natalia; Brum-Corrêa, Marcelo; Paes-Almeida, Oslei; Ajudarte-Lopes, Marcio; Agustin-Vargas, Pablo

    2017-01-01

    Background Hyaline ring granuloma (HRG) of the oral cavity is an uncommon disorder considered to be a foreign-body reaction resulting from implantation of food vegetable particles. Microscopically, it is characterized by the presence of structures of hyaline rings in an inflamed fibrous tissue background, which contains multinucleated giant cells. Material and Methods We present the case of a 4-year-old boy diagnosed with a mandible osseous HRG, which showed clinical and tomographic aspects suggestive of an aggressive bone tumor. Results The patient underwent surgical exploration and histopathologic analysis showed fragments composed predominantly of widespread dense connective tissue with an acute and chronic inflammatory infiltrate containing multinucleated giant cells and scattered areas of eosinophilic material associated with hyaline rings, strongly suggestive of vegetable particles. The eosinophilic material was positive for periodic acid-Schiff (PAS) and resistant to diastase digestion. These features led to diagnosis of osseous HRG. Scanning electron microscopy (SEM) analysis was performed for illustrative purposes and the multiple structures resembling vegetable particles were characterized in more detail. Conclusions Although rare, this case highlights the importance of the clinician’s awareness regarding the existence of an osseous counterpart of HRG. Key words:Agenesis of the corpus callosum, child, hyaline ring granuloma, intraosseous, mandible, pulse granuloma. PMID:28210458

  6. Single-shot T1 mapping of the corpus callosum: a rapid characterization of fiber bundle anatomy.

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    Hofer, Sabine; Wang, Xiaoqing; Roeloffs, Volkert; Frahm, Jens

    2015-01-01

    Using diffusion-tensor magnetic resonance imaging and fiber tractography the topographic organization of the human corpus callosum (CC) has been described to comprise five segments with fibers projecting into prefrontal (I), premotor and supplementary motor (II), primary motor (III), and primary sensory areas (IV), as well as into parietal, temporal, and occipital cortical areas (V). In order to more rapidly characterize the underlying anatomy of these segments, this study used a novel single-shot T1 mapping method to quantitatively determine T1 relaxation times in the human CC. A region-of-interest analysis revealed a tendency for the lowest T1 relaxation times in the genu and the highest T1 relaxation times in the somatomotor region of the CC. This observation separates regions dominated by myelinated fibers with large diameters (somatomotor area) from densely packed smaller axonal bundles (genu) with less myelin. The results indicate that characteristic T1 relaxation times in callosal profiles provide an additional means to monitor differences in fiber anatomy, fiber density, and gray matter in respective neocortical areas. In conclusion, rapid T1 mapping allows for a characterization of the axonal architecture in an individual CC in less than 10 s. The approach emerges as a valuable means for studying neocortical brain anatomy with possible implications for the diagnosis of neurodegenerative processes.

  7. Single-shot T1 mapping of the corpus callosum: A rapid characterization of fiber bundle anatomy

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    Sabine eHofer

    2015-05-01

    Full Text Available Using diffusion-tensor MRI and fiber tractography the topographic organization of the corpus callosum (CC has been described to comprise 5 segments with fibers projecting into prefrontal (I, premotor and supplementary motor (II, primary motor (III, and primary sensory areas (IV, as well as into parietal, temporal, and occipital cortical areas (V. In order to more rapidly characterize the underlying anatomy of these segments, this study used a novel single-shot T1 mapping method to quantitatively determine T1 relaxation times in the human CC. A region-of-interest analysis revealed a tendency for the lowest T1 relaxation times in the genu and the highest T1 relaxation times in the somatomotor region of the CC. This observation separates regions dominated by myelinated fibers with large diameters (somatomotor area from densely packed smaller axonal bundles (genu with less myelin. The results indicate that characteristic T1 relaxation times in callosal profiles provide an additional means to monitor differences in fiber anatomy, fiber density, and gray matter in respective neocortical areas. In conclusion, rapid T1 mapping allows for a characterization of the axonal architecture in an individual CC in less than 10 s. The approach emerges as a valuable means for studying neocortical brain anatomy with possible implications for the diagnosis of neurodegenerative processes.

  8. MR imaging findings of the corpus callosum region in the differentiation between multiple sclerosis and neuromyelitis optica

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    Chen, Zhiye, E-mail: yyqf@hotmail.com [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Feng, Feng, E-mail: cjr.fengfeng@vip.163.com [Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 1 Shuaifuyuan, Wangfujing, Beijing 100730 (China); Yang, Yang, E-mail: whitean0584@sina.com.cn [Department of Neurology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Li, Jinfeng, E-mail: lijf_301@163.com [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China); Ma, Lin, E-mail: cjr.malin@vip.163.com [Department of Radiology, PLA General Hospital, 28 Fuxing Road, Beijing 100853 (China)

    2012-11-15

    Purpose: To evaluate MR imaging findings in corpus callosum region for the discrimination between opticospinal multiple sclerosis (OSMS) and neuromyelitis optica (NMO). Materials and methods: Forty-two definite OSMS with seronegative NMO-IgG and 23 NMO with seropositive NMO-IgG, and 27 age-matched normal controls (NC) were recruited. Sagittal T2-FLAIR images with 2-mm slice thickness were obtained. Subcallosal dot-dash (SCDD) sign and subcallosal striations (SCS) sign were reviewed. Results: SCDD was more commonly detected in OSMS (28 of 42 patients) than in NMO (5 of 23 patients) (P < 0.05). SCS showed no difference between OSMS (31 of 42 patients) and NMO (12 of 23 patients) (P > 0.05). For comparing ROC analysis among SCDD, SCS, and SCDD + SCS for predicted probability through binary logistic regression analysis, SCDD + SCS had the largest area under ROC curve (0.777) than SCDD (0.725) and SCS (0.608). Conclusion: SCDD may be helpful in distinguishing OSMS from NMO. The regression equation may also be a simple and effective method of choice for the differentiation between OSMS and NMO.

  9. Hereditary spastic paraplegia associated with thin corpus callosum Paraplegia espástica hereditária associada a hipoplasia de corpo caloso

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    Hélio A. Ghizoni Teive

    2001-09-01

    Full Text Available Autosomal recessive hereditary spastic paraplegia (AR-HSP associated with thin corpus callosum was recently described in Japan, and most families were linked to chromosome 15q13-15. We report two patients from two different Brazilian families with progressive gait disturbance starting at the second decade of life, spastic paraparesis, and mental deterioration. One patient presented cerebellar ataxia. Magnetic resonance imaging (MRI of the head of both patients showed a thin corpus callosum. AR-HSP with a thin corpus callosum is a rare disorder, mainly described in Japanese patients. We found only 4 Caucasian families with AR-HSP with thin corpus callosum described in the literature. Further studies including additional Caucasian families of AR-HSP with thin corpus callosum are required to delineate the genetic profile of this syndrome in occidental countries.A paraplegia espástica hereditária autossômica recessiva (PEH-AR associada com hipoplasia de corpo caloso foi inicialmente descrita no Japão. Estudos de ligação genética mostram que a maioria das famílias estão relacionadas ao cromossomo 15q13-15. Relatamos dois pacientes de famílias brasileiras, não relacionadas, com distúrbio de marcha com início na segunda década de vida, paraparesia espástica e comprometimento das funções cognitivas. Um dos pacientes apresentava ataxia cerebelar. A ressonância magnética de encéfalo de ambos os pacientes mostrou hipoplasia de corpo caloso. PEH-AR associada com hipoplasia de corpo caloso é uma condição rara, descrita principalmente em pacientes do Japão. Encontramos apenas 4 famílias caucasianas com PEH-AR e hipoplasia de corpo caloso. Mais estudos com famílias caucasianas são necessários para delinear o perfil genético dessa síndrome em países ocidentais.

  10. Congenital malformations of the supratentorial brain. Pt. 2. Disorders of the corpus callosum and holoprosencephalies; Kongenitale Malformationen des Grosshirns. Teil 2: Entwicklungsstoerungen des Balkens und Holoprosenzephalien

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    Rummeny, C. [Institut fuer Klinische Radiologie, Klinikum der Universitaet Muenchen, Grosshadern, Muenchen (Germany); Institut fuer klinische Radiologie, Klinikum der Universitaet Muenchen, Grosshadern, Marchioninistrasse 15, 81377, Muenchen (Germany); Ertl-Wagner, B.; Reiser, M.F. [Institut fuer Klinische Radiologie, Klinikum der Universitaet Muenchen, Grosshadern, Muenchen (Germany)

    2003-11-01

    The corpus callosum is formed between the 7th and the 20th gestational week. If this process is disrupted, partial or complete callosal agenesis may ensue. As large parts of the supra- and infratentorial brain are created druing this critical period, associated anomalies need always to be searched for when callosal agenesis is present. Associations with neuro-genetic syndromes also exist. The corpus callosum is generally formed from front to back (''front-to-back rule''). Therefore, a partial callosal agenesis usually involves the posterior portion of the corpus callosum, while a secondary lesion of the corpus callosum does not follow this rule. Holoprosencephalies are a notable exception to this rule, as the frontal part of the corpus callosum is absent in spite of their classification as congenital malformations. They represent a disturbance of the differentiation and cleavage of the prosencephalon with a disruption of the separation of the cerebral hemispheres. Holoprosencephalies can be due to genetic causes, but also to intrauterine infections or other teratogenic causes. The holoprosencephalies are subdivided into alobar, semilobar and lobar holoprosencephalies. This article aims to describe the most important features of callosal agenesis and holoprosencephalies highlighting the respective imaging characteristics. (orig.) [German] Die Anlage des Balkens findet in der 7.-20. Woche nach Gestation statt. Stoerungen in dieser Entwicklungsphase koennen zu einer Balkenagenesie oder zu einer Balkenhypogenesie fuehren. Da in diesem Entwicklungsstadium grosse Anteile des Gross- und Kleinhirns angelegt werden, muss immer nach assoziierten Anlagestoerungen gesucht werden. Ebenso treten auch Kombinationen mit genetisch bedingten Syndromen auf. Die Entwicklung des Balkens folgt der sog. anterioren-posterioren Sequenz (''front-to-back rule''). Sekundaere Schaedigungen bei der Balkenentwicklung folgen dieser Regel nicht, und lassen

  11. Segmentation and Analysis of Corpus Callosum in Alzheimer MR Images using Total Variation Based Diffusion Filter and Level Set Method.

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    Anandh, K R; Sujatha, C M; Ramakrishnan, S

    2015-01-01

    Alzheimer’s Disease (AD) is a common form of dementia that affects gray and white matter structures of brain. Manifestation of AD leads to cognitive deficits such as memory impairment problems, ability to think and difficulties in performing day to day activities. Although the etiology of this disease is unclear, imaging biomarkers are highly useful in the early diagnosis of AD. Magnetic resonance imaging is an indispensible non-invasive imaging modality that reflects both the geometry and pathology of the brain. Corpus Callosum (CC) is the largest white matter structure as well as the main inter-hemispheric fiber connection that undergoes regional alterations due to AD. Therefore, segmentation and feature extraction are predominantly essential to characterize the CC atrophy. In this work, an attempt has been made to segment CC using edge based level set method. Prior to segmentation, the images are pre-processed using Total Variation (TV) based diffusion filtering to enhance the edge information. Shape based geometric features are extracted from the segmented CC images to analyze the CC atrophy. Results show that the edge based level set method is able to segment CC in both the normal and AD images. TV based diffusion filtering has performed uniform region specific smoothing thereby preserving the texture and small scale details of the image. Consequently, the edge map of CC in both the normal and AD are apparently sharp and distinct with continuous boundaries. This facilitates the final contour to correctly segment CC from the nearby structures. The extracted geometric features such as area, perimeter and minor axis are found to have the percentage difference of 5.97%, 22.22% and 9.52% respectively in the demarcation of AD subjects. As callosal atrophy is significant in the diagnosis of AD, this study seems to be clinically useful.

  12. Assessing corpus callosum changes in Alzheimer's disease: comparison between tract-based spatial statistics and atlas-based tractography.

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    Maria Giulia Preti

    Full Text Available Tractography based on Diffusion Tensor Imaging (DTI represents a valuable tool for investigating brain white matter (WM microstructure, allowing the computation of damage-related diffusion parameters such as Fractional Anisotropy (FA in specific WM tracts. This technique appears relevant in the study of pathologies in which brain disconnection plays a major role, such as, for instance, Alzheimer's Disease (AD. Previous DTI studies have reported inconsistent results in defining WM abnormalities in AD and in its prodromal stage (i.e., amnestic Mild Cognitive Impairment; aMCI, especially when investigating the corpus callosum (CC. A reason for these inconsistencies is the use of different processing techniques, which may strongly influence the results. The aim of the current study was to compare a novel atlas-based tractography approach, that sub-divides the CC in eight portions, with Tract-Based Spatial Statistics (TBSS when used to detect specific patterns of CC FA in AD at different clinical stages. FA data were obtained from 76 subjects (37 with mild AD, 19 with aMCI and 20 elderly healthy controls, HC and analyzed using both methods. Consistent results were obtained for the two methods, concerning the comparisons AD vs. HC (significantly reduced FA in the whole CC of AD patients and AD vs. aMCI (significantly reduced FA in the frontal portions of the CC in AD patients, thus identifying a relative preservation of the frontal CC regions in aMCI patients compared to AD. Conversely, the atlas-based method but not the TBSS showed the ability to detect a selective FA change in the CC parietal, left temporal and occipital regions of aMCI patients compared to HC. This finding indicates that an analysis including a higher number of voxels (with no restriction to tract skeletons may detect characteristic pattern of FA in the CC of patients with preclinical AD, when brain atrophy is still modest.

  13. The myelinated fiber loss in the corpus callosum of mouse model of schizophrenia induced by MK-801.

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    Xiu, Yun; Kong, Xiang-ru; Zhang, Lei; Qiu, Xuan; Gao, Yuan; Huang, Chun-xia; Chao, Feng-lei; Wang, San-rong; Tang, Yong

    2015-04-01

    Previous magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) investigations have shown that the white matter volume and fractional anisotropy (FA) were decreased in schizophrenia (SZ), which indicated impaired white matter integrity in SZ. However, the mechanism underlying these abnormalities has been less studied. The current study was designed to investigate the possible reasons for white matter abnormalities in the mouse model of SZ induced by NMDA receptor antagonist using the unbiased stereological methods and transmission electron microscope technique. We found that the mice treated with MK-801 demonstrated a series of schizophrenia-like behaviors including hyperlocomotor activity and more anxiety. The myelinated fibers in the corpus callosum (CC) of the mice treated with MK-801 were impaired with splitting lamellae of myelin sheaths and segmental demyelination. The CC volume and the total length of the myelinated fibers in the CC of the mice treated with MK-801 were significantly decreased by 9.4% and 16.8% when compared to those of the mice treated with saline. We further found that the loss of the myelinated fibers length was mainly due to the marked loss of the myelinated nerve fibers with the diameter of 0.4-0.5 μm. These results indicated that the splitting myelin sheaths, demyelination and the loss of myelinated fibers with small diameter might provide one of the structural bases for impaired white matter integrity of CC in the mouse model of SZ. These results might also provide a baseline for further studies searching for the treatment of SZ through targeting white matter.

  14. The ciliogenic transcription factor RFX3 regulates early midline distribution of guidepost neurons required for corpus callosum development.

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    Carine Benadiba

    Full Text Available The corpus callosum (CC is the major commissure that bridges the cerebral hemispheres. Agenesis of the CC is associated with human ciliopathies, but the origin of this default is unclear. Regulatory Factor X3 (RFX3 is a transcription factor involved in the control of ciliogenesis, and Rfx3-deficient mice show several hallmarks of ciliopathies including left-right asymmetry defects and hydrocephalus. Here we show that Rfx3-deficient mice suffer from CC agenesis associated with a marked disorganisation of guidepost neurons required for axon pathfinding across the midline. Using transplantation assays, we demonstrate that abnormalities of the mutant midline region are primarily responsible for the CC malformation. Conditional genetic inactivation shows that RFX3 is not required in guidepost cells for proper CC formation, but is required before E12.5 for proper patterning of the cortical septal boundary and hence accurate distribution of guidepost neurons at later stages. We observe focused but consistent ectopic expression of Fibroblast growth factor 8 (Fgf8 at the rostro commissural plate associated with a reduced ratio of GLIoma-associated oncogene family zinc finger 3 (GLI3 repressor to activator forms. We demonstrate on brain explant cultures that ectopic FGF8 reproduces the guidepost neuronal defects observed in Rfx3 mutants. This study unravels a crucial role of RFX3 during early brain development by indirectly regulating GLI3 activity, which leads to FGF8 upregulation and ultimately to disturbed distribution of guidepost neurons required for CC morphogenesis. Hence, the RFX3 mutant mouse model brings novel understandings of the mechanisms that underlie CC agenesis in ciliopathies.

  15. Corpus callosum damage predicts disability progression and cognitive dysfunction in primary-progressive MS after five years.

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    Bodini, Benedetta; Cercignani, Mara; Khaleeli, Zhaleh; Miller, David H; Ron, Maria; Penny, Sophie; Thompson, Alan J; Ciccarelli, Olga

    2013-05-01

    We aim to identify specific areas of white matter (WM) and grey matter (GM), which predict disability progression and cognitive dysfunction after five years in patients with primary-progressive multiple sclerosis (PPMS). Thirty-two patients with early PPMS were assessed at baseline and after five years on the Expanded Disability Status Scale (EDSS), and EDSS step-changes were calculated. At year five, a subgroup of 25 patients and 31 healthy controls underwent a neuropsychological assessment. Baseline imaging consisted of dual-echo (proton density and T2-weighted), T1-weighted volumetric, and diffusion tensor imaging. Fractional anisotropy (FA) maps were created, and fed into tract-based spatial statistics. To compensate for the potential bias introduced by WM lesions, the T1 volumes underwent a lesion-filling procedure before entering a voxel-based morphometry protocol. To investigate whether FA and GM volume predicted EDSS step-changes over five years and neuropsychological tests scores at five years, voxelwise linear regression analyses were performed. Lower FA in the splenium of the corpus callosum (CC) predicted a greater progression of disability over the follow-up. Lower FA along the entire CC predicted worse verbal memory, attention and speed of information processing, and executive function at five years. GM baseline volume did not predict any clinical variable. Our findings highlight the importance of damage to the interhemispheric callosal pathways in determining physical and cognitive disability in PPMS. Disruption of these pathways, which interconnect motor and cognitive networks between the two hemispheres, may result in a disconnection syndrome that contributes to long-term physical and cognitive disability.

  16. Response inhibition deficits in children with Fetal Alcohol Spectrum Disorder: Relationship between diffusion tensor imaging of the corpus callosum and eye movement control

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    Angelina Paolozza

    2014-01-01

    Full Text Available Response inhibition is the ability to suppress irrelevant impulses to enable goal-directed behavior. The underlying neural mechanisms of inhibition deficits are not clearly understood, but may be related to white matter connectivity, which can be assessed using diffusion tensor imaging (DTI. The goal of this study was to investigate the relationship between response inhibition during the performance of saccadic eye movement tasks and DTI measures of the corpus callosum in children with or without Fetal Alcohol Spectrum Disorder (FASD. Participants included 43 children with an FASD diagnosis (12.3 ± 3.1 years old and 35 typically developing children (12.5 ± 3.0 years old both aged 7–18, assessed at three sites across Canada. Response inhibition was measured by direction errors in an antisaccade task and timing errors in a delayed memory-guided saccade task. Manual deterministic tractography was used to delineate six regions of the corpus callosum and calculate fractional anisotropy (FA, mean diffusivity (MD, parallel diffusivity, and perpendicular diffusivity. Group differences in saccade measures were assessed using t-tests, followed by partial correlations between eye movement inhibition scores and corpus callosum FA and MD, controlling for age. Children with FASD made more saccade direction errors and more timing errors, which indicates a deficit in response inhibition. The only group difference in DTI metrics was significantly higher MD of the splenium in FASD compared to controls. Notably, direction errors in the antisaccade task were correlated negatively to FA and positively to MD of the splenium in the control, but not the FASD group, which suggests that alterations in connectivity between the two hemispheres of the brain may contribute to inhibition deficits in children with FASD.

  17. Origins and development of corpus callosum and fornix commissures in mice*%胼胝体与穹窿连合纤维的来源与发育

    Institute of Scientific and Technical Information of China (English)

    吴萍; 邓同兴; 赵慧杰; 李明善; 邓锦波

    2011-01-01

    目的:研究小鼠胼胝体联合和穹窿连合的发生、发育以及细胞来源.方法: 利用快蓝活体示踪和DiI离体示踪技术对不同日龄的胚胎以及生后胼胝体联合和穹窿连合进行了顺行和逆行示踪.结果: 穹窿连合约在胚胎第16天左右形成,而胼胝体连合在胚胎18天左右形成.穹窿连合的纤维主要由海马CA3区锥体细胞、门细胞及内嗅皮质和下托锥体细胞所发出,而胼胝体联合可以由位于新皮质Ⅱ~Ⅵ层神经细胞所投射.结论: 胼胝体连合在细胞来源和分布上的广泛性是大脑半球两侧新皮质之间大量的信息交换的需要.%Objective: To investigate the origin and development of corpus callosum and fornix commissures. Methods: The prenatal and postnatal corpus callosum and fornix commissures at various ages in mice were labeled anterogradely and retrogradely with fast blue tracing in vivo and DiI tracing in vitro. Results: Fornix commissure was formed at embryonic day 16,and corpus callosum commissure was formed at about embryonic day 18. The fibers of fornix rose from the pyramidal cells of CA3, hilus, subiculum and entorhinal cortex. However, fornix fibers were projected by the neurons from layers Ⅱ- Ⅵ of neocortex. Conclusion: The widely cellular distribution of corpus callosum is required of the numerous message communications between two neocortices.

  18. Self-referential and social cognition in a case of autism and agenesis of the corpus callosum

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    Lombardo Michael V

    2012-11-01

    Full Text Available Abstract Background While models of autism spectrum conditions (ASC are emerging at the genetic level of analysis, clear models at higher levels of analysis, such as neuroanatomy, are lacking. Here we examine agenesis of the corpus callosum (AgCC as a model at the level of neuroanatomy that may be relevant for understanding self-referential and social-cognitive difficulties in ASC. Methods We examined performance on a wide array of tests in self-referential and social-cognitive domains in a patient with both AgCC and a diagnosis of ASC. Tests included a depth-of-processing memory paradigm with self-referential and social-cognitive manipulations, self-report measures of self-consciousness, alexithymia, and empathy, as well as performance measures of first-person pronoun usage and mentalizing ability. The performance of the AgCC patient was compared to a group of individuals with ASC but without AgCC and with neurotypical controls. These comparison groups come from a prior study where group differences were apparent across many measures. We used bootstrapping to assess whether the AgCC patient exhibited scores that were within or outside the 95% bias-corrected and accelerated bootstrap confidence intervals observed in both comparison groups. Results Within the depth-of-processing memory paradigm, the AgCC patient showed decreased memory sensitivity that was more extreme than both comparison groups across all conditions. The patient’s most pronounced difficulty on this task emerged in the social-cognitive domain related to information-processing about other people. The patient was similar to the ASC group in benefiting less from self-referential processing compared to the control group. Across a variety of other self-referential (i.e. alexithymia, private self-consciousness and social-cognitive measures (i.e. self-reported imaginative and perspective-taking subscales of empathy, mentalizing, the AgCC patient also showed more extreme scores than

  19. Dysgenesis of the corpus callosum and associated malformaaation{sup :} computed tomography and magnetic resonance imaging findings; Disgenesia do corpo caloso e mas-formacoes associadas: achados de tomografia computadorizada e ressonancia magnetica

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    Montandon, Cristiano; Montandon Junior, Marcelo Eustaquio [Colegio Brasileiro de Radiologia e Diagnostico por Imagem (CBR), Sao Paulo, SP (Brazil); Ribeiro, Flavia Aparecida de Sousa; Lobo, Leonardo Valadares Barbosa; Teixeira, Kim-Ir-Sen Santos [Goias Univ., Goiania (Brazil). Hospital de Clinicas. Dept. de Diagnostico por Imagem e Anatomia Patologica]. E-mail: cabeca2@terra.com.br

    2003-10-01

    Callosal dysgenesis is a malformation of the corpus callosum with origins in the embryogenesis of the telencephalon. We reviewed the computed tomography and magnetic resonance imaging findings of 11 patients with callosal dysgenesis and one patient with normal corpus callosum associated with a lipoma. The patients were divided into three distinct groups: total agenesis (three patients), partial agenesis (six patients) and hypoplasia (two patients). Associated abnormalities were observed in nine patients, including Chiari II malformation (one patient), schizencephaly (one patient), interhemispheric cyst (two patients), Dandy-Walker cyst (one patient), nodular heterotopy (one patient) and lipoma of the corpus callosum (four patients). This paper presents a review that may contribute to the diagnosis of these disorders. (author)

  20. Impact of in utero exposure to EtOH on corpus callosum development and paw preference in rats: protective effects of silymarin

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    Montoya Rebecca

    2002-11-01

    Full Text Available Abstract Background Using a rat model we have found that the bioflavonoid silymarin (SY ameliorates some of the negative consequences of in utero exposure to ethanol (EtOH. In the current study our aim was to determine if laterality preference and corpus callosum development were altered in rat offspring whose mothers were provided with a concomitant administration of SY with EtOH throughout gestation. Methods We provided pregnant Fisher/344 rats with liquid diets containing 35% ethanol derived calories (EDC throughout the gestational period. A silymarin/phospholipid compound containing 29.8% silybin was co administered with EtOH to a separate experimental group. We tested the offspring for laterality preference at age 12 weeks. After testing the rats were sacrificed and their brains perfused for later corpus callosum extraction. Results We observed incomplete development of the splenium in the EtOH-only offspring. Callosal development was complete in all other treatment groups. Rats from the EtOH-only group displayed a left paw preference; whereas control rats were evenly divided between right and left paw preference. Inexplicably both SY groups were largely right paw preferring. Conclusions The addition of SY to the EtOH liquid diet did confer some ameliorative effects upon the developing fetal rat brain.

  1. Forced abstinence from cocaine self-administration is associated with DNA methylation changes in myelin genes in the corpus callosum: a preliminary study

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    David Andrew Nielsen

    2012-06-01

    Full Text Available Background: Human cocaine abuse is associated with alterations in white matter integrity revealed upon brain imaging, an observation that is recapitulated in an animal model of continuous cocaine exposure. The mechanism through which cocaine may affect white matter is unknown and the present study tested the hypothesis that cocaine self-administration results in changes in DNA methylation that could result in altered expression of several myelin genes that could contribute to the effects of cocaine on white matter integrity.Methods: In the present study, we examined the impact of forced abstinence from cocaine self-administration on chromatin-associated changes in white matter. To this end, rats were trained to self-administer cocaine (0.75 mg/kg/0.1 ml infusion for 14 days followed by forced abstinence for 1 day (N = 6 or 30 days (N = 6 before sacrifice. Drug-free, sham surgery controls (n = 7 were paired with the experimental groups. Global DNA methylation and DNA methylation at specific CpG sites in the promoter regions of myelin basic protein (Mbp, proteolipid protein-1 (Plp1, and SRY-related HMG-box-10 (Sox10 genes were analyzed in DNA extracted from corpus callosum.Results: Significant differences in the overall methylation patterns of the Sox10 promoter region were observed in the corpus callosum of rats at 30 days of forced abstinence from cocaine self-administration relative to sham controls; the -189, -142, -93 and -62 CpG sites were significantly hypomethylated point-wise at this time point. After correction for multiple comparisons, no differences in global methylation or the methylation patterns of Mbp or Plp1 were found.Conclusions: Forced abstinence from cocaine self-administration was associated with differences in DNA methylation at specific CpG sites in the promoter region of the Sox10 gene in corpus callosum. These changes may be related to reductions in normal age related changes in DNA methylation and could be a factor in

  2. Corpus callosum of diabetic foot decompression intervention%糖尿病足胼胝减压干预治疗的效果

    Institute of Scientific and Technical Information of China (English)

    王威

    2011-01-01

    Objective To explore the treatment effects of removal of plantar calluses on healing of diabetic foot and preventing its relapse. Methods A total of 452 patients with diabetic foot, 260 cases were under the corpus callosum ulcer with local ulcer infection, in which 161 cases were treated with decompression therapy, and 99 cases did not participate in decompression treatment; 98 of 192 cases were ulcers healed under the corpus callosum continues decompression in treatment, and 94 cases did not participate in decompression treatment. Results Healing time under the corpus callosum and foot clearance combined with infection in decompression treatment group was less than in the non-decompression group (t = - 22. 053, - 64. 568; P <0. 05). 192 ulcer healed cases and 98 decompression cases did not occur ulcer during the observation period.Those 94 cases who did not participate in decompression treatment recurrence local ulcer in short time (6 -42 d). Conclusions Removal of the corpus callosum of diabetic foot can be effective in reducing plantar pressure to promote healing of foot infection and may prevent infection relapse.%目的 探讨足底胼胝去除减压治疗促进糖尿病足愈合及预防感染复发的效果.方法 共452例糖尿病足患者,胼胝下溃疡合并局部溃疡感染者260例参与减压治疗者161例,未参加减压治疗者99例;胼胝下溃疡痊愈后192例继续进行减压治疗者98例,未参加减压治疗者94例.结果 胼胝下感染及合并足间隙感染者减压治疗组较之非减压治疗组其愈合时间明显缩短,组间比较具有统计学意义(t=-22.053,-64.568;P<0.05).胼胝下溃疡痊愈者192例参与减压治疗者98例观察期间未发生局部胼胝下溃疡,未参加减压治疗者94例均在短期内复发,复发时间为6~42 d.结论 去除糖尿病足胼胝可有效减轻足底压力促进足部感染愈合,并可预防感染复发.

  3. Diffusion tensor quantification and cognitive correlates of the macrostructure and microstructure of the corpus callosum in typically developing and dyslexic children.

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    Hasan, Khader M; Molfese, David L; Walimuni, Indika S; Stuebing, Karla K; Papanicolaou, Andrew C; Narayana, Ponnada A; Fletcher, Jack M

    2012-11-01

    Noninvasive quantitative MRI methods, such as diffusion tensor imaging (DTI), can offer insights into the structure-function relationships in human developmental brain disorders. In this article, we quantified the macrostructural and microstructural attributes of the corpus callosum (CC) in children with dyslexia and in typically developing readers of comparable age and gender. Diffusion anisotropy, and mean, radial and axial diffusivities of cross-sectional CC subregions were computed using a validated DTI methodology. The normalized posterior CC area was enlarged in children with dyslexia relative to that in typically developing children. Moreover, the callosal microstructural attributes, such as the mean diffusivity of the posterior middle sector of the CC, correlated significantly with measures of word reading and reading comprehension. Reading group differences in fractional anisotropy, mean diffusivity and radial diffusivity were observed in the posterior CC (CC5). This study demonstrates the utility of regional DTI measurements of the CC in understanding the neurobiology of reading disorders.

  4. Cambios en el cuerpo calloso posteriores a derivación ventricular: Descripción de dos casos y revisión del tema Imaging changes in the corpus callosum after ventricular shunting: Case reports and literature review

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    Santiago Vallejo

    2012-09-01

    Full Text Available Se presentan dos pacientes sometidos a derivación ventricular por hidrocefalia idiopática y cisticercosis del cuarto ventrículo, respectivamente. En la resonancia magnética (RM de control se encontró un aumento en el tamaño del cuerpo calloso con zonas de prolongación de los tiempos de relajación sin restricción en la secuencia de difusión. Las teorías fisiopatológicas mencionan: efectos mecánicos directos tras la colocación de la derivación, efecto compresivo crónico sobre el cuerpo calloso contra la hoz cerebral por la hidrocefalia, tracción de ramas perforantes de las arterias pericallosas que conduce a isquemia (probablemente ausente en estudios prequirúrgicos por el adelgazamiento del cuerpo calloso y descompresión, luego de la derivación, que produce reexpansión del cuerpo calloso y edema intersticial del mismo. Los hallazgos pueden explicarse por el antecedente de derivación e hidrocefalia sin repercusión clínica aparente.We report the cases of two patients with ventricular drainage due to idiopathic hydrocephalus and fourth ventricle cysticercosis, respectively. A follow-up MRI demonstrated increased volume of the corpus callosum with areas of prolonged relaxation without restriction on water diffusion sequences. Pathophysiologic theories include direct mechanical effects after the catheter insertion, chronic compression of the corpus callosum against the falx due to hydrocephalus, ischemia due to elongation of perforating pericallosal arteries not detected before shunting due to thinning of the corpus callosum, and decompressive changes leading to corpus callosum expansion and interstitial edema. These findings might be related to the history of ventricular shunt and hydrocephalus with no apparent clinical significance.

  5. Structural integrity of the corpus callosum predicts long-term transfer of fluid intelligence-related training gains in normal aging.

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    Wolf, Dominik; Fischer, Florian Udo; Fesenbeckh, Johanna; Yakushev, Igor; Lelieveld, Irene Maria; Scheurich, Armin; Schermuly, Ingrid; Zschutschke, Lisa; Fellgiebel, Andreas

    2014-01-01

    Although cognitive training usually improves cognitive test performance, the capability to transfer these training gains into respective or functionally related cognitive domains varies significantly. Since most studies demonstrate rather limited transfer effects in older adults, aging might be an important factor in transfer capability differences. This study investigated the transfer capability of logical reasoning training gains to a measure of Fluid Intelligence (Gf) in relation to age, general intelligence, and brain structural integrity as measured by diffusion tensor imaging. In a group of 41 highly educated healthy elderly, 71% demonstrated successful transfer immediately after a 4-week training session (i.e. short-term transfer). In a subgroup of 22% of subjects transfer maintained over a 3-month follow-up period (i.e. long-term transfer). While short-term transfer was not related to structural integrity, long-term transfer was associated with increased structural integrity in corpus and genu of the corpus callosum. Since callosal structural integrity was also related to age (in the present and foregoing studies), previously observed associations between age and transfer might be moderated by the structural integrity. Surprisingly, age was not directly associated with transfer in this study which could be explained by the multi-dependency of the structural integrity (modulating factors beside age, e.g. genetics). In this highly educated sample, general intelligence was not related to transfer suggesting that high intelligence is not sufficient for transfer in normal aging. Further studies are needed to reveal the interaction of transfer, age, and structural integrity and delineate mechanisms of age-dependent transfer capabilities.

  6. Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains

    Science.gov (United States)

    Sergeant, C.; Vesvres, M. H.; Devès, G.; Guillou, F.

    2005-04-01

    In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter.

  7. Adult-onset deficiency in growth hormone and insulin-like growth factor-I alters oligodendrocyte turnover in the corpus callosum.

    Science.gov (United States)

    Hua, Kun; Forbes, M Elizabeth; Lichtenwalner, Robin J; Sonntag, William E; Riddle, David R

    2009-08-01

    Growth hormone (GH) and insulin-like growth factor-I (IGF-I) provide trophic support during development and also appear to influence cell structure, function and replacement in the adult brain. Recent studies demonstrated effects of the GH/IGF-I axis on adult neurogenesis, but it is unclear whether the GH/IGF-I axis influences glial turnover in the normal adult brain. In the current study, we used a selective model of adult-onset GH and IGF-I deficiency to evaluate the role of GH and IGF-I in regulating glial proliferation and survival in the adult corpus callosum. GH/IGF-I-deficient dwarf rats of the Lewis strain were made GH/IGF-I replete via twice daily injections of GH starting at postnatal day 28 (P28), approximately the age at which GH pulse amplitude increases in developing rodents. GH/IGF-I deficiency was initiated in adulthood by removing animals from GH treatment. Quantitative analyses revealed that adult-onset GH/IGF-I deficiency decreased cell proliferation in the white matter and decreased the survival of newborn oligodendrocytes. These findings are consistent with the hypothesis that aging-related changes in the GH/IGF-I axis produce deficits in ongoing turnover of oligodendrocytes, which may contribute to aging-related cognitive changes and deficits in remyelination after injury.

  8. Relationship between Stereoscopic Vision, Visual Perception, and Microstructure Changes of Corpus Callosum and Occipital White Matter in the 4-Year-Old Very Low Birth Weight Children

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    Przemko Kwinta

    2015-01-01

    Full Text Available Aim. To assess the relationship between stereoscopic vision, visual perception, and microstructure of the corpus callosum (CC and occipital white matter, 61 children born with a mean birth weight of 1024 g (SD 270 g were subjected to detailed ophthalmologic evaluation, Developmental Test of Visual Perception (DTVP-3, and diffusion tensor imaging (DTI at the age of 4. Results. Abnormal stereoscopic vision was detected in 16 children. Children with abnormal stereoscopic vision had smaller CC (CC length: 53±6 mm versus 61±4 mm; p<0.01; estimated CC area: 314±106 mm2 versus 446±79 mm2; p<0.01 and lower fractional anisotropy (FA values in CC (FA value of rostrum/genu: 0.7±0.09 versus 0.79±0.07; p<0.01; FA value of CC body: 0.74±0.13 versus 0.82±0.09; p=0.03. We found a significant correlation between DTVP-3 scores, CC size, and FA values in rostrum and body. This correlation was unrelated to retinopathy of prematurity. Conclusions. Visual perceptive dysfunction in ex-preterm children without major sequelae of prematurity depends on more subtle changes in the brain microstructure, including CC. Role of interhemispheric connections in visual perception might be more complex than previously anticipated.

  9. 3D pre- versus post-season comparisons of surface and relative pose of the corpus callosum in contact sport athletes

    Science.gov (United States)

    Lao, Yi; Gajawelli, Niharika; Haas, Lauren; Wilkins, Bryce; Hwang, Darryl; Tsao, Sinchai; Wang, Yalin; Law, Meng; Leporé, Natasha

    2014-03-01

    Mild traumatic brain injury (MTBI) or concussive injury affects 1.7 million Americans annually, of which 300,000 are due to recreational activities and contact sports, such as football, rugby, and boxing[1]. Finding the neuroanatomical correlates of brain TBI non-invasively and precisely is crucial for diagnosis and prognosis. Several studies have shown the in influence of traumatic brain injury (TBI) on the integrity of brain WM [2-4]. The vast majority of these works focus on athletes with diagnosed concussions. However, in contact sports, athletes are subjected to repeated hits to the head throughout the season, and we hypothesize that these have an influence on white matter integrity. In particular, the corpus callosum (CC), as a small structure connecting the brain hemispheres, may be particularly affected by torques generated by collisions, even in the absence of full blown concussions. Here, we use a combined surface-based morphometry and relative pose analyses, applying on the point distribution model (PDM) of the CC, to investigate TBI related brain structural changes between 9 pre-season and 9 post-season contact sport athlete MRIs. All the data are fed into surface based morphometry analysis and relative pose analysis. The former looks at surface area and thickness changes between the two groups, while the latter consists of detecting the relative translation, rotation and scale between them.

  10. Selected aspects of social cognition in patient with total agenesis of the corpus callosum (ACC and Arnold-Chiari desease – case study

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    Daniluk, Beata

    2013-06-01

    Full Text Available Aim. The goal of the research was a characteristic of emotional-social competencies and communicative abilities in a 16-years old patient with ACC and Arnold-Chiari disease and higher than average intelligence. Method. RHLB-PL was applied. Results. Total score in RHLB-PL suggested language and communication impairment. The greatest problems were observed in the field of behavioral self-control and discourse abilities. The patient had difficulties in the topic of the discourse maintaining, resisting from production of unconnected topics and comments, interject inappropriate remarks. Problems in humor comprehension and the dissociation between relative high level of written metaphors analysis abilities and low level of Picture Metaphors perception and explanation were observed. Linguistic Prosody was average. Conclusion. Patient M.J. with agenesis of corpus callosum presented high number of deficits typical in right hemisphere damage patients. It is possible to explain that fact in the context of interhemispheric transfer disorders, specially when complex material was processed.

  11. Myelin in the frontal region of corpus callosum in old rats%老年大鼠胼胝体额区有髓神经纤维与髓鞘改变的研究

    Institute of Scientific and Technical Information of China (English)

    徐瑲; 兰欢; 卢伟; 唐勇

    2011-01-01

    目的:探讨老年大鼠胼胝体额区有髓神经纤维、髓鞘的结构变化和髓鞘碱性蛋白(Myelin basic protein,MBP)的表达变化,以及二者间的关系.方法:运用透射电子显微镜和新的体视学方法分别对年轻组和老年组雌性Long-Evans大鼠胼胝体额区有髓神经纤维和髓鞘进行定量研究,运用Western blot对年轻组和老年组大鼠胼胝体额区MBP表达进行定量研究.结果:与年轻组相比,老年组胼胝体额区体积存在显著性降低,有髓神经纤维总体积显著性下降,21.5 kD MBP表达量显著性降低.21.5 kD MBP的表达降低与有髓神经纤维总体积、髓鞘总体积的降低之间呈正相关.结论:胼胝体存在显著性老年萎缩,胼胝体额区有髓神经纤维和MBP的老年改变可能与老年大脑额叶功能下降有关.%Objective : To explore the age-related changes of the mvelinated fihers ,myelin sheath and the expression of myelin basic protein in the frontal region of the corpus callosum in old rats , and their relationship. Methods : The myelinated fibers and sheathes in the frontal region of corpus callosum of young and old-aged female Long-Evans rats were quantitatively studied using electron microscope and unhiased stereological techniques.Myelin basic proteins in the frontal region of corpus callosum of young and old-aged female rats were quantitatively studied using Western hlot. Results : When compared with young female rats, the total volume of the frontal region of the corpus callosum and the total volume of the myelinated fibers in the frontal region of old corpus callosum were significantly degraded. The expression of 21.5 kD MBP was significantly decreased in old rats. The reduction of the expression of 21.5 kD MBP,the reduction of the total volume of the myelinated fihers and the total volume of the myelin sheathes were positively correlated. Conclusion : There is age-related atrophy of the frontal region of corpus callosum. The age

  12. Impairment in explicit visuomotor sequence learning is related to loss of microstructural integrity of the corpus callosum in multiple sclerosis patients with minimal disability.

    Science.gov (United States)

    Bonzano, L; Tacchino, A; Roccatagliata, L; Sormani, M P; Mancardi, G L; Bove, M

    2011-07-15

    Sequence learning can be investigated by serial reaction-time (SRT) paradigms. Explicit learning occurs when subjects have to recognize a test sequence and has been shown to activate the frontoparietal network in both contralateral and ipsilateral hemispheres. Thus, the left and right superior longitudinal fasciculi (SLF), connecting the intra-hemispheric frontoparietal circuits, could have a role in explicit unimanual visuomotor learning. Also, as both hemispheres are involved, we could hypothesize that the corpus callosum (CC) has a role in this process. Pathological damage in both SLF and CC has been detected in patients with Multiple Sclerosis (PwMS), and microstructural alterations can be quantified by Diffusion Tensor Imaging (DTI). In light of these findings, we inquired whether PwMS with minimal disability showed impairments in explicit visuomotor sequence learning and whether this could be due to loss of white matter integrity in these intra- and inter-hemispheric white matter pathways. Thus, we combined DTI analysis with a modified version of SRT task based on finger opposition movements in a group of PwMS with minimal disability. We found that the performance in explicit sequence learning was significantly reduced in these patients with respect to healthy subjects; the amount of sequence-specific learning was found to be more strongly correlated with fractional anisotropy (FA) in the CC (r=0.93) than in the left (r=0.28) and right SLF (r=0.27) (p for interaction=0.005 and 0.04 respectively). This finding suggests that an inter-hemispheric information exchange between the homologous areas is required to successfully accomplish the task and indirectly supports the role of the right (ipsilateral) hemisphere in explicit visuomotor learning. On the other hand, we found no significant correlation of the FA in the CC and in the SLFs with nonspecific learning (assessed when stimuli are randomly presented), supporting the hypothesis that inter

  13. Progressive decline in fractional anisotropy on serial DTI examinations of the corpus callosum: a putative marker of disease activity and progression in SPMS

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    Tian, Wei; Zhu, Tong; Zhong, Jianhui; Liu, Xiang [University of Rochester Medical Center, Department of Imaging Sciences, Rochester, NY (United States); Rao, Praveen; Segal, Benjamin M. [University of Michigan, Department of Neurology, Holtom-Garrett Program in Neuroimmunology, Ann Arbor, MI (United States); Ekholm, Sven [University of Rochester Medical Center, Department of Imaging Sciences, Rochester, NY (United States); University of Rochester Medical Center, Division of Diagnostic and Interventional Neuroradiology, Rochester, NY (United States)

    2012-04-15

    Clinical trials of secondary progressive multiple sclerosis (SPMS) is lacking reliable biomarkers or outcome measures that reflect tissue injury incurred within a 1- to 2-year observation period. Diffusion tensor imaging (DTI) is sensitive in detecting acute brain tissue damage. We monitored SPMS patients over 12 months for diffusion changes within the corpus callosum (CC). Bimonthly MRI examinations over a 1-year period were performed on 11 SPMS patients. The protocol included postcontrast T1-weighted images and DTI. Based on the appearance of T1 enhancing lesion(s) during the study period, the patients were divided into enhancing (five patients) and nonenhancing (six patients) groups. Fractional anisotropy (FA) and mean diffusivity (MD) of the genu, body, and splenium of the CC were measured and temporal changes in mean FA and MD were evaluated for each group as well as between groups. Immunology data from peripheral blood mononuclear cells were also collected on a monthly basis. The enhancing group showed significant, progressive decrease in FA in body (p = 0.012) and splenium (p = 0.033) of CC, and significantly higher lymphotoxin-{beta} levels. No significant FA changes were seen in the nonenhancing group. Moreover, the FA decline in the enhancing group deviated significantly from the nonenhancing group, which remained essentially stable. Although MD increased slightly in both groups, there was no significant difference between the two groups. Based on the MR and immunology findings, the results of our study suggest that DTI undergo more rapid and longitudinal changes in SPMS patients with inflammatory activity. (orig.)

  14. Minimally Invasive Robotic Laser Corpus Callosotomy: A Proof of Concept

    Science.gov (United States)

    Essayed, Walid I; Deb, Sayantan; Hoffman, Caitlin; Schwartz, Theodore H

    2017-01-01

    Introduction We describe the feasibility of using minimally invasive robotic laser interstitial thermotherapy (LITT) for achieving an anterior two-thirds as well as a complete corpus callosotomy. Methods Ten probe trajectories were plotted on normal magentic resonance imaging (MRI) scans using the Brainlab Stereotactic Planning Software (Brainlab, Munich, Germany). The NeuroBlate® System (Monteris Medical, MN, USA) was used to conform the thermal burn to the corpus callosum along the trajectory of the probe. The distance of the ideal entry site from either the coronal suture and the torcula or nasion and the midline was calculated. The distance of the probe tip from the dorsal and ventral limits of the callosotomy in the sagittal plane were also calculated. Results Anterior two-thirds callosotomy was possible in all patients using a posterior parieto-occipital paramedian trajectory through the non-dominant lobe. The average entry point was 3.64 cm from the midline, 10.6 cm behind the coronal suture, and 9.2 cm above the torcula. The probe tip was an average of 1.4 cm from the anterior commissure. For a total callosotomy, an additional contralaterally placed frontal probe was used to target the posterior one-third of the corpus callosum. The average entry site was 3.3 cm from the midline and 9.1 cm above the nasion. The average distance of the probe tip from the base of the splenium was 0.94 cm. Conclusion The directional thermoablation capability of the NeuroBlate® system allows for targeted lesioning of the corpus callosum, to achieve a two-thirds or complete corpus callosotomy. A laser distance of < 2 cm is sufficient to reach the entire corpus callosum through one trajectory for an anterior two-thirds callosotomy and two trajectories for a complete callosotomy.

  15. Clinical, neuroimaging and cytogenetic findings in 20 patients with corpus callosum dysgenesis Achados clínicos, citogenéticos e de neuroimagem em 20 pacientes com disgenesia do corpo caloso

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    Anna Cláudia Evangelista dos Santos

    2002-06-01

    Full Text Available Twenty children with corpus callosum agenesis or hypoplasia were evaluated under a standardized investigation protocol. Psychomotor retardation, seizures, and craniofacial anomalies were the most prominent findings. There were three cases of chromosomal anomalies, all of them representing trisomy of chromosome 8.Vinte pacientes com disgenesia do corpo caloso foram avaliados através de um protocolo padronizado. Retardo neuropsicomotor, convulsões e dismorfias faciais foram os achados mais proeminentes. Três casos de anomalia cromossômica foram observados, todos representados por trissomia do cromossomo 8.

  16. Clinical Analysis on Reversible Splenial Lesions of the Corpus Callosum%可逆性胼胝体压部病变的临床分析

    Institute of Scientific and Technical Information of China (English)

    胡小辉; 姚长江; 汤前军; 刘智舒

    2012-01-01

    Objective To evaluate the clinical characteristics and pathophysiological mechanism of reversible splenial lesions of the corpus callosum (RSLCC). Methods The patients with RSLCC and older than 6 years were screened from "Pubraed" and "Springer" databases for analysis between January 1, 2000 and August 1, 2011. We analyzed their clinical characteristics and the pathophysiological mechanisms. Results The mean age of 14 RSLCC patients, including 7 males and 7 females, were (27.4 ± 15.6) years, ranging from 7 to 58 years. Causes of the disease in these patients were fever, vaccination injection, infection, seizure, anti-epileptic drug or acute withdrawal of antiepileptic drug, tetracycline therapy, 5-fluorouracil treatment, malnutrition, chronic alcoholism. The appearance rate of clinical representations was 50%, which included visual hallucinations, delusion, disorientation, confusion, gait ataxia, acute urinary retention. The mean interval to disappearance of RSLCC was (20.6 ± 14.5) days, ranging from 2 to 50 days. The magnetic resonance imaging of abnormality in RSLCC were hypo- or isointense on T1 weight imaging (T1WI) without Gd-enhancement, hyperintense on T2 weight imaging (T2WI) and diffusion-weighted imaging (DWI) with or without fluid-attenuated inversion recovery (FLAIR), hypointense on apparent diffusion coefficient (ADC). Conclusions The causes of RSLCC are diverse. The representations of RSLCC are complicated. The pathophysiological mechanism is cytotoxic edema probably caused by hyponatremia, hypoglycemia, dysfunction of arginine-vasopressin or infectious and toxic agents to splenial of the corpus callosum.%目的 探讨可逆性胼胝体压部病变的临床特征和致病机制.方法 总结Pubmed和Springer数据库中2000年1月1日-2011年8月1日报道的年龄>6岁的可逆性胼胝体压部病变患者的临床特征,分析该病可能的致病机制.结果 14例患者中男7例,女7例;年龄(27.4±15.6)岁,最小7岁,最大58岁;病

  17. 遗传性痉挛性截瘫伴薄胼胝体6例报道并文献复习%Hereditary spastic paraplegia with thin corpus callosum(6 case report and literature review)

    Institute of Scientific and Technical Information of China (English)

    马凌燕; 万新华; 王琳; 徐蔚海; 杨英麦

    2012-01-01

    Objective To investigate the pathogenesis, clinical characteristics, imaging changes and prognosis of hereditary spastic paraplegia with thin corpus callosum (HSP-TCC), Methods Clinical presentation and imaging features of six patients with hereditary spastic paraplegia and thin carpus callosum were reported. The clinical features were summarized and the related literatures were reviewed. Results All six cases had a juvenile onset, presenting with spastic gait, tendon hyperreflexia and positive Babinski sign and without sensory disturbance. Two cases showed ataxia. No one had urination and defecation function disturbance. Conclusions HSP-TCC is a type of complicated forms of hereditary spastic paraplegia (HSP) and is characterized with spastic paraplegia and thin corpus callosum. The pathogenesis is unclear and the prognosis is poor.%目的 探讨遗传性痉挛性截瘫伴薄胼胝体(HSP-TCC)的发病机制、临床特点、影像学表现及预后.方法 分析6例HSP-TCC患者的临床及影像学表现,结合文献复习总结其临床特征.结果 6例患者均青少年起病,表现为痉挛步态,腱反射亢进,病理征阳性,2例有共济失调.患者均无感觉障碍及大小便障碍.全部患者头颅MRI显示胼胝体变薄.结论 HSP-TCC作为复杂型遗传性痉挛性截瘫(HSP)的一种,临床上以双下肢痉挛性截瘫和薄胼胝体为特征,发病机制尚不清楚,预后较差.

  18. MRI显示的儿童胼胝体压部孤立性病变的临床特征分析%The clinical characteristics of children with splenium of corpus callosum solitary lesions displayed on MRI

    Institute of Scientific and Technical Information of China (English)

    李朝阳; 李春花; 杨洁

    2014-01-01

    Objective To explore the prominent clinical features and the prognosis of corpus callosum solitary lesions cases in children.Methods There were 16 cases with corpus callosum solitary lesions receiving treatment at our hospital from January to December 2013.All of the clinical features were collected and retrospectively analyzed.Results The 16 cases aged 1 year to 13 years with an average age of (3.44 ± 3.65) years.The causes of the disease included the viral encephalitis,convulsions,and rotavirus infection.The most prevalent disorders were convulsions (10 cases),gastrointestinal symptoms (8 cases),fever (8 cases),positive cervical resistance (6 cases),fatigue (5 cases),altered states of consciousness (2 cases),headache (1 case),and dizziness (1 case).Corpus callosum lesions lasted for 13-50 days,with an average of (28.8 ± 10.2) days.Cranial magnetic resonance showed the splenium of the corpus callosum with isolated oval lesions,low signal on T1 weighted images and apparent diffusion coefficient images,high signal on T2 weighted images and diffusion weighted images.Conclusions The splenium of the corpus callosum lesions of children occur in a lower rate than adults with the etiology including intracranial infection,convulsions and rotavirus infection.Main clinical manifestations include fever,convulsions and gastrointestinal symptoms (nausea,diarrhea,etc).The cases followed-up showed the lesions and symptoms are reversible,and the prognosis is good.%目的 探讨儿童胼胝体压部病变的临床特征及预后.方法 回顾性分析2013年1-12月山西省儿童医院神经内科收治的胼胝体压部病变患者的临床特征及预后,分析该病可能的致病机制.结果 16例患者中,男性8例,女性8例;年龄1 ~13岁,平均(3.44±3.65)岁;病因分为病毒性脑炎、抽搐、轮状病毒感染等;出现的临床症状包括抽搐(10例)、消化道症状(8例)、发热(8例)、颈抵抗阳性(6例)、精神萎靡(5例)、意识改变(2

  19. Association between Cognitive Impairment and Corpus Callosum Network Connectivity in Leukoaraiosis%胼胝体网络连接性与脑白质疏松认知功能损害的相关性

    Institute of Scientific and Technical Information of China (English)

    何育生; 江虹; 李云霞; 腾飞; 聂志余

    2016-01-01

    目的通过弥散张量成像(diffusion tensor imaging,DTI)研究脑白质疏松(leukoaraiosis,LA)患者胼胝体网络连接性改变,并探讨其与认知功能损害的关系。  方法本研究为前瞻性单中心研究。纳入30例法泽卡斯量表(Fazekas scale)评分为2~3级的LA患者及20例头部磁共振成像正常的对照组。依据是否存在认知功能损害将LA组再分为认知正常与轻度认知功能损害2个亚组。所有被研究对象均进行脑血管危险因素登记、血液生化检查、认知功能评估筛查及3.0T头部磁共振成像检查及DTI检查。认知评估采用中文版蒙特利尔认知评估(Montreal Cognitive Assessment,MoCA)量表及简易智力状况检查(Mini-mental State Examination,MMSE)量表。使用PANDA软件处理DTI数据,提取胼胝体膝部、体部及压部的部分各向异性(fractional anisotropy,FA)和平均扩散系数(mean diffusivity,MD)数值。采用Pearson相关分析研究DTI数据变化与认知功能损害的关系。  结果 LA组与对照组的性别、年龄、受教育情况、脑血管病常规危险因素及血生化之间差异无显著性,P>0.05。LA组的MMSE及MoCA分值低于对照组,P值分别为0.002和0.008。LA组胝体膝部(P=0.000)、体部(P=0.000)、压部(P=0.026)3个部位的FA值均低于对照组,而MD值高于对照组,P值分别为0.013、0.006及0.007。LA组MMSE及MoCA分值降低与胼胝体膝部、体部、压部的FA下降均成正相关,但相关系数从膝部(r=0.78)到压部(r=0.41)呈现逐渐递减趋势。  结论 L A存在胼胝体网络连接性改变,胼胝体FA下降与认知功能损害密切相关。%Objective To study the changes of corpus callosum network connectivity in leukoaraiosis (LA) patients by diffusion tensor imaging (DTI), and investigate the association between this change and cognitive impairment. Methods This study is a single

  20. 高岭土诱导大鼠脑积水模型的建立和监测%Kaolin- induced hydrocephalus in the rat: temporal sequence of changes in weight, intracranial pressure, ventriculomegaly and corpus callosum thickness

    Institute of Scientific and Technical Information of China (English)

    卫永旭; 王伟军; 宋菡姝; 靳世辉; 高瑞庭; 初明; 蔺友志

    2012-01-01

    Objective To develop models of kaolin - induced hydrocephalus in adult Wistar rats and to measure changes of body weight,intracranial pressure,ventriculomegaly and corpus callosum thickness.Methods 60 adult male Wistar rats were randomly divided into experimental group and control group.In the former group,40 rats were randomly separated into 5 subgroups:group A,B,C,D and E,then were used to construct animal models of hydrocephalus by injecting 0.1 ml volume of 25% kaolin sterile solution into the cisterna Magana with the aid of a surgical microscope.Controls were trcatcd in the same way with injection of saline.Body weighing,MRI and ICP were performed at the tine point of 3 days,1,2,4 and 8 weeks after kaolin injection,respectively.Corpus callosum thickness was measured at the level of the optic chiasm.Results Hydrocephalus was induced in 23 rats whose ventricular system expauded as times went on.In hydrocephalus rats,body weight was significantly lower than in age - matched saline - injected sham controls,ICP increased rapidly on day 3 post intracisternal kaolin injection,reached a maximum on day 7,remained markedly elevated through 8 week, and had reduced corpus callosum thickness as ventricle enlargment.Conclusions Kaolin injection through cistern magna can effectively eatablish a rat model of communicating hydrocephalus.Aherations in ICP,ventriculomegaly and corpus callosum thickness occurs sequentially,and the time - course of each manifestation of hydrocephalus differs.%目的 高岭土诱导Wistar大鼠脑积水后系统监测大鼠体质量、颅内压、脑室面积和胼胝体厚度的改变.方法 雄性Wistar大鼠60只,按随机数字表顺序分为实验组(n=40)和对照组(n=20).实验组40只大鼠再随机分为A、B、C、D、E五个亚组,向枕大池内注入25%无菌高岭土混悬液0.1 ml;对照组注入等量无菌生理盐水,注入后3d、1周、2周、4周和8周后行体质量、MRI检查及颅内压监测,经视交叉切

  1. 产前三维超声TUI技术对胎儿胼胝体发育不全的诊断价值%Value of Tomographic Ultrasound Imaging in Prenatal Diagnosis of Fetal Agenesis of the Corpus Callosum

    Institute of Scientific and Technical Information of China (English)

    林琪; 范海波; 甘晗靖; 孙枫; 吴瑛

    2013-01-01

    Objective To analyze the graphic features of fetal agenesis of the corpus callosum (ACC) detected by tomographic ultrasound imaging(TUI) and assess the value of TUI in the ACC. Methods 3D volume data of 35 cases of fetus with ACC were analyzed with TUI,the sagittal plane median view of the brain was obtained and the outcome was compared with that of two-dimensional (2D) ultrasound. Results There was difference in the revealing rate of ACC between TUI and 2D ultrasound(P<0. 05). Conclusions TUI is a useful tool in the prenatal diagnosis of ACC.%目的 分析三维断层超声显像技术(tomographic ultrasound imaging,TUI)在胎儿胼胝体发育不全(agenesis of the corpus callosum,ACC)中的图像特征,评价TUI诊断胎儿胼胝体发育不全的价值.方法 应用TUI对34例二维可疑ACC的三维容积数据进行后处理分析,获得显示胼胝体最好的胎头正中矢状切面,并将结果与二维超声结果进行比较.结果 TUI技术对ACC的显示率为97.0% (33/34);二维超声对ACC的显示率为52.9% (18/34),二者的显示率差别有统计意义(P<0.05).结论 三维超声TUI技术在胎儿ACC的产前诊断上具有较高的应用价值.

  2. Microsurgical endoscopy-assisted anterior corpus callosotomy for drug-resistant epilepsy in an adult unresponsive to vagus nerve stimulation

    Directory of Open Access Journals (Sweden)

    Davide Nasi

    2016-01-01

    Full Text Available Because most of the corpus callosotomy (CC series available in literature were published before the advent of vagus nerve stimulation (VNS, the efficacy of CC in patients with inadequate response to VNS remains unclear, especially in adult patients. We present the case of a 21-year-old female with medically refractory drop attacks that began at the age of 8 years, which resulted in the patient being progressively unresponsive to vagus nerve stimulation implanted at the age of 14 years. Corpus callosotomy was recommended to reduce the number of drop attacks. However, the patient had only mild cognitive impairments and no neurological deficits. For this reason, we were forced to plan a surgical approach able to maximize the disconnection for good seizure control while, at the same time, minimizing sequelae from disconnection syndromes and neurosurgical complications because in such cases of long-lasting epilepsy the gyri cinguli and the arteries can be tenaciously adherent and dislocated with all the normal anatomy altered. In this scenario, we opted for a microsurgical endoscopy-assisted anterior two-thirds corpus callosotomy. The endoscopic minimally invasive approach proved to be quite adequate in this technically demanding case and confirmed that CC may offer advantages, with good results, even in adult patients with drop attacks who have had inadequate response to VNS.

  3. Study of age and sex differences of genu and rostrum of corpus callosum by using diffusion tensor imaging of MRI in normal person%正常人胼胝体膝部及嘴部年龄与性别差异的DTI研究

    Institute of Scientific and Technical Information of China (English)

    卢姿蓉; 邹松; 李振龙; 赵英杰

    2012-01-01

    目的:研究胼胝体膝部和嘴部的DTI参数ADC值、部分各项异性(FA)值及神经密度在年龄及性别方面的差异,并获取其随年龄增长的变化规律.方法:将247例正常人按照年龄段分为10组,行颅脑DTI,测量胼胝体膝部和嘴部ROI的ADC值、FA值及神经纤维数,并计算神经密度.结果:①男性胼胝体膝部和嘴部的ADC值随年龄增长的差异均具有统计学意义;女性则差异均无统计学意义.②男性及女性胼胝体膝部和嘴部的FA值随年龄增长差异均具有统计学意义,其随年龄增长的变化规律基本上符合升高—相对稳定—下降的趋势.③男性及女性的胼胝体膝部和嘴部神经密度随年龄增长差异均无统计学意义.④在>3~6岁组,女性胼胝体嘴部的ADC值显著高于男性(P<0.01);在40岁以上男性,胼胝体膝部的神经密度显著高于女性(P<0.01);胼胝体膝部的ADC值和FA值、胼胝体嘴部的FA值和神经密度在各个年龄段内的性别差异均无统计学意义.结论:①胼胝体膝部和嘴部的ADC值、FA值随年龄增长的变化规律可以反映胼胝体膝部和嘴部生长发育及老化的整个过程.②本研究所获得的胼胝体膝部和嘴部的ADC值、FA值及神经密度可作为以后进一步研究的参考.%Objective: To research the differences of MRI ADC value, FA value and nerve density of the genu and rostrum of corpus callosum in the aspects of age and sex,and obtain the change laws with age. Method:247 normal persons were classified into ten groups according to their age and their heads were examined with DTI and DTT of MRI. The ADC value,FA value and nerve fiber number of the ROIs of genu and rostrum of corpus callosum were measured,and then the nerve density was calculated. Results;①There were significant differences in the ADC values of genu and rostrum of corpus callosum of males with age. The ADC values of genu and rostrum of corpus callosum of females had no

  4. The role of prenatal ultrasound and MRI in diagnosis of fetal agenesis of corpus callosum%胎儿胼胝体缺如产前超声及磁共振诊断的应用分析

    Institute of Scientific and Technical Information of China (English)

    兰为顺; 杨小红; 夏薇; 刘芳; 余旭东; 袁先宏; 李琳; 苏永学; 杨文忠; 陈欣林

    2015-01-01

    目的分析胎儿胼胝体缺如的产前超声及磁共振诊断价值。方法对2013年7月至2014年12月湖北省妇幼保健院产前超声筛查怀疑胼胝体缺如的67例胎儿于超声检查后3 d内行颅脑磁共振检查,与引产或出生后检查结果对照,对产前超声及磁共振检查结果进行分析。结果产前超声怀疑胼胝体缺如的67例胎儿磁共振检查后均证实为胼胝体缺如,其中胼胝体完全缺如58例,胼胝体部分缺如9例(均为胼胝体体部和压部缺如)。胎儿胼胝体缺如在磁共振正中矢状位图像上表现为胼胝体完全或部分缺如,脑回呈放射状排列;在横轴位和冠状位图像上表现为侧脑室轻至中度扩张,形态失常。结论磁共振对胎儿胼胝体缺如有较高的诊断价值,可作为产前超声的补充和验证方法,在产前超声检查怀疑胎儿胼胝体异常时,应行胎儿磁共振检查明确诊断。超声与磁共振联合筛查,是胎儿中枢神经系统畸形产前检查中重要的影像学诊断方法。%Objective To discuss the value of prenatal ultrasound and MRI in diagnosis of fetal agenesis of corpus callosum (ACC). Methods Sixty-seven fetuses from Hubei Maternal and Children's Hospital performed fetal MRI from July 2013 to December 2014 were included in this study. All fetuses (67 cases) with suspected ACC were studied with a 1.5T MR unit within 3 days after ultrasound examination. Prenatal ultrasound and MRI findings were studied. Results All the 67 ACCs previously suspected on ultrasound were confirmed by MRI. Among the 67 ACCs, 58 cases were complete ACC and 9 cases were partial ACC. Corpus callosum body and/or splenium absence was found in all 9 partial ACC cases. In all cases, on MRI, corpus callosum complete or partial absence was showed on the median sagittal images, and mild to moderate ventriculomegaly and abnormal morphology in lateral ventricle was shown on the axial or coronary images

  5. Interhemispheric Connections between the Primary Visual Cortical Areas via the Anterior Commissure in Human Callosal Agenesis.

    Science.gov (United States)

    van Meer, Nathalie; Houtman, Anne C; Van Schuerbeek, Peter; Vanderhasselt, Tim; Milleret, Chantal; Ten Tusscher, Marcel P

    2016-01-01

    Aim: In humans, images in the median plane of the head either fall on both nasal hemi-retinas or on both temporal hemi-retinas. Interhemispheric connections allow cortical cells to have receptive fields on opposite sides. The major interhemispheric connection, the corpus callosum, is implicated in central stereopsis and disparity detection in front of the fixation plane. Yet individuals with agenesis of the corpus callosum may show normal stereopsis and disparity vergence. We set out to study a possible interhemispheric connection between primary visual cortical areas via the anterior commissure to explain this inconsistency because of the major role of these cortical areas in elaborating 3D visual perception. Methods: MRI, DTI and tractography of the brain of a 53-year old man with complete callosal agenesis and normal binocular single vision was undertaken. Tractography seed points were placed in both the right and the left V1 and V2. Nine individuals with both an intact corpus callosum and normal binocularity served as controls. Results: Interhemispheric tracts through the anterior commissure linking both V1 and V2 visual cortical areas bilaterally were indeed shown in the subject with callosal agenesis. All other individuals showed interhemispheric visual connections through the corpus callosum only. Conclusion: Callosal agenesis may result in anomalous interhemispheric connections of the primary visual areas via the anterior commissure. It is proposed here that these connections form as alternative to the normal callosal pathway and may participate in binocularity.

  6. 胎儿胼胝体发育不全的超声诊断及临床分析%The Ultrasonographic Diagnosis of Fetal Corpus Callosum Agenesis and Clinical Analysis

    Institute of Scientific and Technical Information of China (English)

    程桂静; 杨太珠; 徐红; 张波

    2012-01-01

    Objective To investigate the ultrasonographic characteristics, cerebral and extracerebral malformation, chromosomal abnormality and prognosis of fetal corpus callosum agenesis( ACC). Methods 36 cases of fetal ACC were retrospectively analyzed from January 2008 to April 2011 in our hospital. Results 36 cases of fetal ACC were diagnosed by ultrasonography, with 19 cases combined other parts of malformation. The diagnostic results with MRI were as the same as with ultrasound in 4 cases. 31 cases were performed Down syndrome screening, which were high risk in 16 cases. 12 cases were performed chromosomal screening, with 1 case of 18 - trisomy and 1 case of inv 9. In the following up, 29 cases were performed induced abortion, 4 cases were birth, and 3 cases were lost of follow up. Conclusions The fetal ACC is often associated with other parts of malformation, prenatal ultrasonic examination can make the preliminary diagnosis for this disease. When ultrasonographic diagnosis of this disease is not clear, MRI can be used as auxiliary method to provide effective clinical information, which can provide the evidence for making suitable decision.%目的 探讨胎儿胼胝体发育不全(agenesis of corpus callosum,ACC)的超声特点、合并的颅内外畸形、染色体及预后状况.方法 回顾性分析我院2008年1月~2011年4月产前超声诊断为胎儿ACC的胎儿共36例.结果 超声诊断为胎儿ACC 36例,其中19例合并其他部位畸形;4例孕妇行核磁共振检查,其结果与超声诊断一致;31例行唐氏筛查,16例为唐氏高风险;12例行染色体检查,1例18-三体综合征,1例9号臂间倒位核型(inv 9).随访结果中,29例进行了引产,4例出生,3例失访.结论 胎儿ACC常合并其他部位的畸形,产前超声检查能够为胎儿ACC作出初步诊断,当超声不能明确诊断时,MRI可以作为辅助检查方法,为制定适合的决策提供依据.

  7. Comparative analysis of ultrasonic and MRI in diagnosis of fetal agenesis of corpus callosum%超声及MRI诊断胎儿胼胝体发育不全的对比分析

    Institute of Scientific and Technical Information of China (English)

    邹丽华; 康敏; 杨家翔; 赵婧; 石涛

    2014-01-01

    目的 探讨产前超声对胎儿胼胝体发育不全(agenesis of the corpus callosum,ACC)的诊断价值及临床意义.方法 对超声诊断胼胝体发育不全的17例胎儿,结合核磁共振(MRI)、出生后或引产结果进行分析比较.结果 17例超声诊断完全型ACC 6例,部分型ACC 11例;2例完全型ACC及1例部分型ACC的超声结论与MRI检查结果一致,5例完全型ACC及7例部分型ACC与引产或出生后结果一致;13例行染色体检查,4例染色体异常;9例合并其它畸形或多种畸形并存.结论 产前超声检查对诊断胎儿ACC特别是完全型ACC具有一定的优势,胎儿ACC常合并其它畸形,MRI是诊断胎儿ACC的必要手段.

  8. A new locus (SPG46) maps to 9p21.2-q21.12 in a Tunisian family with a complicated autosomal recessive hereditary spastic paraplegia with mental impairment and thin corpus callosum.

    Science.gov (United States)

    Boukhris, Amir; Feki, Imed; Elleuch, Nizar; Miladi, Mohamed Imed; Boland-Augé, Anne; Truchetto, Jérémy; Mundwiller, Emeline; Jezequel, Nadia; Zelenika, Diana; Mhiri, Chokri; Brice, Alexis; Stevanin, Giovanni

    2010-10-01

    Hereditary spastic paraplegia (HSP) with thin corpus callosum (TCC) and mental impairment is a frequent subtype of complicated HSP, often inherited as an autosomal recessive (AR) trait. It is clear from molecular genetic analyses that there are several underlying causes of this syndrome, with at least six genetic loci identified to date. However, SPG11 and SPG15 are the two major genes for this entity. To map the responsible gene in a large AR-HSP-TCC family of Tunisian origin, we investigated a consanguineous family with a diagnosis of AR-HSP-TCC excluded for linkage to the SPG7, SPG11, SPG15, SPG18, SPG21, and SPG32 loci. A genome-wide scan was undertaken using 6,090 SNP markers covering all chromosomes. The phenotypic presentation in five patients was suggestive of a complex HSP that associated an early-onset spastic paraplegia with mild handicap, mental deterioration, congenital cataract, cerebellar signs, and TCC. The genome-wide search identified a single candidate region on chromosome 9, exceeding the LOD score threshold of +3. Fine mapping using additional markers narrowed the candidate region to a 45.1-Mb interval (15.4 cM). Mutations in three candidate genes were excluded. The mapping of a novel AR-HSP-TCC locus further demonstrates the extensive genetic heterogeneity of this condition. We propose that testing for this locus should be performed, after exclusion of mutations in SPG11 and SPG15 genes, in AR-HSP-TCC families, especially when cerebellar ataxia and cataract are present.

  9. Impaired visual short-term memory capacity is distinctively associated with structural connectivity of the posterior thalamic radiation and the splenium of the corpus callosum in preterm-born adults.

    Science.gov (United States)

    Menegaux, Aurore; Meng, Chun; Neitzel, Julia; Bäuml, Josef G; Müller, Hermann J; Bartmann, Peter; Wolke, Dieter; Wohlschläger, Afra M; Finke, Kathrin; Sorg, Christian

    2017-02-07

    Preterm birth is associated with an increased risk for lasting changes in both the cortico-thalamic system and attention; however, the link between cortico-thalamic and attention changes is as yet little understood. In preterm newborns, cortico-cortical and cortico-thalamic structural connectivity are distinctively altered, with increased local clustering for cortico-cortical and decreased integrity for cortico-thalamic connectivity. In preterm-born adults, among the various attention functions, visual short-term memory (vSTM) capacity is selectively impaired. We hypothesized distinct associations between vSTM capacity and the structural integrity of cortico-thalamic and cortico-cortical connections, respectively, in preterm-born adults. A whole-report paradigm of briefly presented letter arrays based on the computationally formalized Theory of Visual Attention (TVA) was used to quantify parameter vSTM capacity in 26 preterm- and 21 full-term-born adults. Fractional anisotropy (FA) of posterior thalamic radiations and the splenium of the corpus callosum obtained by diffusion tensor imaging were analyzed by tract-based spatial statistics and used as proxies for cortico-thalamic and cortico-cortical structural connectivity. The relationship between vSTM capacity and cortico-thalamic and cortico-cortical connectivity, respectively, was significantly modified by prematurity. In full-term-born adults, the higher FA in the right posterior thalamic radiation the higher vSTM capacity; in preterm-born adults this FA-vSTM-relationship was inversed. In the splenium, higher FA was correlated with higher vSTM capacity in preterm-born adults, whereas no significant relationship was evident in full-term-born adults. These results indicate distinct associations between cortico-thalamic and cortico-cortical integrity and vSTM capacity in preterm-and full-term-born adults. Data suggest compensatory cortico-cortical fiber re-organization for attention deficits after preterm delivery.

  10. Anterior corpus callosotomy in multistep invasive monitoring and surgery for atonic seizures

    Directory of Open Access Journals (Sweden)

    Van Tri Truong

    2014-01-01

    Full Text Available Identifying the epileptogenic zone (EZ in patients with refractory nonlesional frontal lobe epilepsy is frequently challenging. Intracranial EEG (icEEG recordings are often required to better delineate the EZ, but the presence of an extensive network of connections allowing rapid ictal spread may result in bilateral homologous regional (or extremely diffuse electrical ictal patterns. Here, we report a case where callosotomy performed after a first nonlateralizing icEEG study allowed for adequate identification of the EZ. The patient, an 18-year-old left-handed woman with daily atonic spells, had synchronous interictal and ictal epileptic activity from both supplementary motor areas (SMAs during icEEG. Anterior partial callosotomy localized the EZ to the right SMA, as seizures were no longer associated with mirror-image ictal activity over the left SMA. Right SMA resection led to seizure freedom (follow-up of 23 months. This case exemplifies how a partial callosotomy followed by further icEEG recordings may adequately localize the EZ when initial icEEG recordings reveal bilateral synchronous focal or regional ictal activities.

  11. Disgenesia do corpo caloso e más-formações associadas: achados de tomografia computadorizada e ressonância magnética Dysgenesis of the corpus callosum and associated malformations: computed tomography and magnetic resonance imaging findings

    Directory of Open Access Journals (Sweden)

    Cristiano Montandon

    2003-10-01

    Full Text Available O termo disgenesia do corpo caloso refere-se a uma má-formação deste com origem na embriogênese do telencéfalo. O relato analisa os achados de tomografia computadorizada e ressonância magnética em 11 pacientes com disgenesia calosa e em um caso de corpo caloso normal com lipoma associado. Esta pode ser distinguida em três grupos: agenesia total (três casos, agenesia parcial (seis casos e hipoplasia (dois casos. Anomalias associadas foram observadas em nove casos, incluindo má-formação de Chiari tipo II (um caso, esquizencefalia (um caso, cisto inter-hemisférico (dois casos, heterotopia nodular (um caso, cisto de Dandy-Walker (um caso e lipoma do corpo caloso (quatro casos. Este artigo demonstra um espectro destes distúrbios, auxiliando na sua interpretação diagnóstica.Callosal dysgenesis is a malformation of the corpus callosum with origins in the embryogenesis of the telencephalon. We reviewed the computed tomography and magnetic resonance imaging findings of 11 patients with callosal dysgenesis and one patient with normal corpus callosum associated with a lipoma. The patients were divided into three distinct groups: total agenesis (three patients, partial agenesis (six patients and hypoplasia (two patients. Associated abnormalities were observed in nine patients, including Chiari II malformation (one patient, schizencephaly (one patient, interhemispheric cyst (two patients, Dandy-Walker cyst (one patient, nodular heterotopy (one patient and lipoma of the corpus callosum (four patients. This paper presents a review that may contribute to the diagnosis of these disorders.

  12. Clinical Correlates of Corpus Callosal Agenesis

    OpenAIRE

    J Gordon Millichap

    1998-01-01

    The clinical correlates of agenesis of the corpus callosum were examined in 56 cases (37 adult, 19 pediatric) reported to the British Neurological Surveillance Unit (BNSU) and surveyed at the Department of Psychological Medicine, Institute of Psychiatry, London, UK.

  13. Corpus Callosum Morphology in Children Who Stutter

    Science.gov (United States)

    Choo, Ai Leen; Chang, Soo-Eun; Zengin-Bolatkale, Hatun; Ambrose, Nicoline G.; Loucks, Torrey M.

    2012-01-01

    Multiple studies have reported both functional and neuroanatomical differences between adults who stutter and their normally fluent peers. However, the reasons for these differences remain unclear although some developmental data suggest that structural brain differences may be present in school-age children who stutter. In the present study, the…

  14. 胎儿胼胝体发育不良的超声和磁共振对比观察%Comparison of ultrasound and MRI in the prenatal diagnosis of agenesis of corpus callosum

    Institute of Scientific and Technical Information of China (English)

    姜小力; 邓学东; 李晓兵

    2011-01-01

    Objective To observe the value of ultrasound (US) and MRI in the prenatal diagnosis of agenesis of corpus callosum (ACC).Methods Fetal ACC was suspected in 16 pregnant women by prenatal US.Fetal MRI was performed within 3 days after prenatal US.The findings of prenatal US and fetal MRI were compared with the results of autopsy or following up imaging data after birth.Results Sixteen fetuses were detected in 16 pregnant women.Fourteen fetuses of ACC suspected with prenatal US were confirmed with MRI (5 confirmed with following-up after birth and 9 with autopsy).Another 2 fetuses were not ACC, 1 was ventriculomegaly companying with gray matter translocation and the other was cerebral white matter and brain stem hypoplasia.Of all the fetal ACC confirmed with MRI, US was consistent with MRI in 7 fetuses, and other 7 fetuses were suspected with US.For the other associated abnormalities in central nervous system,MRI was consistent with prenatal US in 7 fetuses.MRI demonstrated more associated abnormalities than US in 4 fetuses.Conclusion US is the optimal choice for detecting fetal anomalies.However, MRI is superior to US in the diagnosis of ACC and contributes to the definite diagnosis of ACC and possible associated abnormalities.%目的 探讨超声与MRI在胎儿胼胝体发育不良(ACC)产前诊断中的应用价值.方法 超声怀疑胎儿ACC孕妇16名,均在超声检查后3天内接受胎儿MR检查.将超声、MRI结果与出生后或引产后结果对照.结果 16名孕妇共检出胎儿16胎,MRI证实14胎为胎儿ACC(出生后随访证实5胎,引产后证实9胎),1胎为单纯双侧脑室扩张伴灰质易位,1胎为脑白质、脑干发育不良.MRI与超声比较,诊断胎儿ACC一致者7胎;超声可疑、MRI肯定者7胎;对于其伴发中枢神经系统畸形,两者一致者7胎,MRI多于超声者4胎.结论 超声检查是产前筛查胎儿ACC的普遍方法;MRI对胎儿ACC的显示明显优于超声,有助于明确诊断胎儿ACC并判断其分型及合并畸形.

  15. Isolated complete corpus callosal agenesis

    OpenAIRE

    Jaiganesh S, Venkateshwaran A, Naresh Kumar C, Rajasekhar KV

    2014-01-01

    Isolated complete corpus callosal agenesis is a rare entity. Usually this condition will be an associated finding in other syndromes. 3 month old male child came with complaints of deformed foot on both sides, not having a social smile and neck holding. Patient referred to the Radiology department for MRI brain which showed complete absence of corpus callosum, widely separated and parallely placed lateral ventricles, colpocephaly, high riding of 3rd ventricle and absence of cingulate gyrus an...

  16. Isolated complete corpus callosal agenesis

    Directory of Open Access Journals (Sweden)

    Jaiganesh S, Venkateshwaran A, Naresh Kumar C, Rajasekhar KV

    2014-11-01

    Full Text Available Isolated complete corpus callosal agenesis is a rare entity. Usually this condition will be an associated finding in other syndromes. 3 month old male child came with complaints of deformed foot on both sides, not having a social smile and neck holding. Patient referred to the Radiology department for MRI brain which showed complete absence of corpus callosum, widely separated and parallely placed lateral ventricles, colpocephaly, high riding of 3rd ventricle and absence of cingulate gyrus and radial arrangement of gyri along the interhemispheric fissure. Hence it was reported as isolated complete corpus callosal agenesis and this article describes the Embryogenesis, anatomy, developmental anomalies and its clinical manifestations & prognosis.

  17. The role of the anterior commissure in callosal agenesis.

    Science.gov (United States)

    Barr, Melodie S; Corballis, Michael C

    2002-10-01

    Two individuals with callosal agenesis (J.P. and M.M.) and 10 neurologically normal participants were tested on tasks requiring interhemispheric visual integration. M.M., whose anterior commissure was within normal limits, was much worse at matching colors and letters between visual fields than within visual fields, whereas J.P., whose anterior commissure was greatly enlarged, showed no evidence of interhemispheric disconnection. This suggests that in some cases of callosal agenesis, probably a minority, an enlarged anterior commissure may compensate for the lack of the corpus callosum. Neither acallosal participant showed interhemispheric disconnection on tasks requiring integration of location and orientation, however, suggesting that the anterior commissure plays no role in such tasks. These tasks may depend on subcortical commissures, such as the intertectal commissure.

  18. Involuntary masturbation and hemiballismus after bilateral anterior cerebral artery infarction.

    Science.gov (United States)

    Bejot, Yannick; Caillier, Marie; Osseby, Guy-Victor; Didi, Roy; Ben Salem, Douraied; Moreau, Thibault; Giroud, Maurice

    2008-02-01

    Ischemia of the areas supplied by the anterior cerebral artery is relatively uncommon. In addition, combined hemiballismus and masturbation have rarely been reported in patients with cerebrovascular disease. We describe herein a 62-year-old right-handed man simultaneously exhibiting right side hemiballismus and involuntary masturbation with the left hand after bilateral infarction of the anterior cerebral artery territory. Right side hemiballismus was related to the disruption of afferent fibers from the left frontal lobe to the left subthalamic nucleus. Involuntary masturbation using the left hand was exclusively linked to a callosal type of alien hand syndrome secondary to infarction of the right side of the anterior corpus callosum. After 2 weeks, these abnormal behaviours were completely extinguished. This report stresses the wide diversity of clinical manifestations observed after infarction of the anterior cerebral artery territory.

  19. Quantification of structural changes in the corpus callosumin children with profound hypoxic-ischaemic brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Stivaros, Stavros M. [Manchester Academic Health Science Centre, Academic Unit of Paediatric Radiology, Royal Manchester Children' s Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester (United Kingdom); University of Manchester, Centre for Imaging Sciences, Institute of Population Health, Manchester (United Kingdom); Radon, Mark R. [The Walton Centre NHS Foundation Trust, Department of Neuroradiology, Liverpool (United Kingdom); Mileva, Reneta; Gledson, Ann; Keane, John A. [University of Manchester, School of Computer Science, Manchester (United Kingdom); Connolly, Daniel J.A.; Batty, Ruth [Sheffield Children' s Hospital NHS Foundation Trust, Department of Neuroradiology, Sheffield (United Kingdom); Cowell, Patricia E. [University of Sheffield, Department of Human Communication Sciences, Sheffield (United Kingdom); Hoggard, Nigel; Griffiths, Paul D. [University of Sheffield, Academic Unit of Radiology, Sheffield (United Kingdom); Wright, Neville B.; Tang, Vivian [Manchester Academic Health Science Centre, Academic Unit of Paediatric Radiology, Royal Manchester Children' s Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester (United Kingdom)

    2016-01-15

    Birth-related acute profound hypoxic-ischaemic brain injury has specific patterns of damage including the paracentral lobules. To test the hypothesis that there is anatomically coherent regional volume loss of the corpus callosum as a result of this hemispheric abnormality. Study subjects included 13 children with proven acute profound hypoxic-ischaemic brain injury and 13 children with developmental delay but no brain abnormalities. A computerised system divided the corpus callosum into 100 segments, measuring each width. Principal component analysis grouped the widths into contiguous anatomical regions. We conducted analysis of variance of corpus callosum widths as well as support vector machine stratification into patient groups. There was statistically significant narrowing of the mid-posterior body and genu of the corpus callosum in children with hypoxic-ischaemic brain injury. Support vector machine analysis yielded over 95% accuracy in patient group stratification using the corpus callosum centile widths. Focal volume loss is seen in the corpus callosum of children with hypoxic-ischaemic brain injury secondary to loss of commissural fibres arising in the paracentral lobules. Support vector machine stratification into the hypoxic-ischaemic brain injury group or the control group on the basis of corpus callosum width is highly accurate and points towards rapid clinical translation of this technique as a potential biomarker of hypoxic-ischaemic brain injury. (orig.)

  20. Effect Comparison of the Treatment of Intractable Epilepsy in Children With Anterior Corpus Callosotomy and Full Corpus Callosotomy%胼胝体前部切开和胼胝全切开治疗儿童难治性癫痫的效果对比

    Institute of Scientific and Technical Information of China (English)

    袁小威; 王新军

    2015-01-01

    目的:探讨难治性癫痫患儿胼胝体切开长度的不同产生的手术效果。方法回顾性研究2013年1月~2014年4月我院收治的38例患有难治性癫痫的儿童,其中24例行胼胝体前部切开术,14例行胼胝体一期全切开术,术后均随访1年,采用改良的Engel分级评估手术效果。结果胼胝体前部切开组:EngelⅠ级5例、EngelⅡ级8例、EngelⅢ级9例、EngelⅣ级2例;胼胝体一期全切开组:EngelⅠ级6例、EngelⅡ级7例、EngelⅢ级1例、EngelⅣ级别0例。结论对于难治性癫痫患儿,胼胝体一期全部切开比胼胝体前部切开更加有效,应在术前充分评估病情及风险的基础上,合理选择手术方式。%ObjectiveTo compare the efficacy of anterior corpus calosotomy and ful corpus calosotomy for treatment in children with intractable epilepsy. Methods Retrospectively analyzed the clinical files of 38 children with intractable epilepsy from January 2013 to April 2014 performed by anterior corpus calosotomy. Patients were folowed up for 1 year,and the effect of the surgery was evaluated according to the modified Engel grading.Results Patients treated with anterior corpus calosotomy: Engel class I 5 cases,Engel class II 8 cases,Engel class III 9 cases,Engel class IV 2 cases. Patients treated with ful corpus calosotomy:Engel class I 6 cases,Engel class II 7 cases,Engel class III 1 cases,Engel class IV 0 cases.Conclusion Anterior corpus calosotomy showed better efficacy in treating children with intractable epilepsy than ful corpus calosotomy.

  1. Agenesis of the corpus callosumina premature infant associated with Langdon-Down syndrome

    Directory of Open Access Journals (Sweden)

    Velisavljev-Filipović Gordana

    2005-01-01

    Full Text Available Introduction Agenesis of the corpus callosum is an abnormality of the part of the brain connecting the two cerebral hemispheres. It can be partial, complete or atypical. The fibers from the cerebral cortex project towards the homotypical region of the contra-lateral cortex passing through the corpus callosum, and crossing the middle line. The absence of corpus callosum causes failure of information transfer from one hemisphere to the other. Children with this anomaly present with learning disabilities and trouble with memorizing facts. Agenesis of corpus callosum may be of syndromic or non-syndromic type. The more common form is the one not associated with any syndrome. The agenesis of corpus callosum is more frequent in male children. Case report This paper presents a child from a twin pregnancy with partial absence of corpus callosum. The pregnancy was not controlled. It ended in premature birth. The afflicted twin is a boy, second in birth order. Apart from agenesis of corpus callosum, he also suffers from Down syndrome. The first twin is healthy, with corpus callosum and with normal karyotype. There was no consanguinity. In the 6th month of pregnancy the mother suffered from infection of the upper respiratory tract that might be the etiological factor of this anomaly. The child was born with hypotrophy, and all anthropometric parameters were below the third percentile. In the neonatal period, the agenesis of corpus callosum was diagnosed by ultrasonic examination and confirmed by CT and MR examinations. The child is now three and a half month old. Active monitoring of the psychical and motor development will show whether there will be any retardation in the psycho-motor development and later deficiency of the higher cortical functions and intelligence. Discussion and Conclusion The clinical characteristics of this anomaly are numerous. They range from asymptomatic cases, with normal intellectual capacity, to severe mental retardation

  2. The effects of quetiapine on myelin morphology and expression of myelin basic protein in the corpus callosum of C57BL/6 mice with chronic alcohol exposure%喹硫平对慢性酒精暴露C57BL/6小鼠胼胝体髓鞘形态和髓鞘碱性蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    刘蒙; 李新娟; 李爽; 张利彬; 韩金红; 赵营; 张瑞岭

    2015-01-01

    差异无统计学意义(t=2.081,P>0.05),喹硫平中、高剂量干预组(0.047±0.04、0.058±0.006)均高于酒精模型组(t=3.301、6.645,均P<0.05);喹硫平组(0.061±0.005)、喹硫平高剂量干预组与对照组相比差异均无统计学意义(t=0.041、1.137,均P>0.05).结论 慢性酒精暴露造成小鼠胼胝体白质髓鞘损伤,学习记忆能力下降;喹硫平中、高剂量干预可能会减轻或者防止慢性酒精使用引起的脑白质髓鞘损伤.%Objective To observe the effects of quetiapine on cognitive function,myelin morphology and expression of myelin basic protein in the corpus callosum of C57BL/6 mice with chronic alcohol exposure.Methods According to random number table,120 male C57BL/6 mice were divided into 6 groups,i.e.,control group,quetiapine control group (10 mg· kg-1· d-1quetiapine),alcohol group,5 mg· kg-1· d1quetiapine plus alcohol group,10 mg· kg-1· d-1 quetiapine plus alcohol group and 15 mg·kg-1· d-1quetiapine plus alcohol group,with 20 mice in each group.Mice in control group and quetiapine control group were maintained with water and solid diet for 20 weeks.Mice in alcohol group and quetiapine plus alcohol groups were maintained with water containing volume fraction of 10% alcohol and solid diet for 20 weeks.Drug with different doses was dissolved in mice drinking for intervention beginning at the 6th week and continuing to the end of the experiment.Morris water maze experiment was used to test the cognitive function.Luxol fast blue (LFB) staining and electron microscopy were used to observe morphology of corpus callosum.The expression of myelin basic protein in the corpus callosum was evaluated with immunofluorescence.Results (1)Morris water maze test showed that the cognition of mice in each group was different (F=4.702,P=0.002).The latency of mice in alcohol group ((22.8 ±5.5) s) was significantly longer compared with that of the control group((1 1.5± 7.1) s,t=3.546,P<0.05).The latency of 5 mg· kg1 · d-1and 10 mg· kg

  3. Positive correlations between corpus callosum thickness and intelligence.

    Science.gov (United States)

    Luders, Eileen; Narr, Katherine L; Bilder, Robert M; Thompson, Paul M; Szeszko, Philip R; Hamilton, Liberty; Toga, Arthur W

    2007-10-01

    Callosal morphology is thought to reflect the capacity for inter-hemispheric communication and thus, in addition to other cerebral characteristics, may serve as a neuroanatomical substrate of general intellectual capacity. We applied novel computational mesh-based methods to establish the presence and direction of correlations between intelligence and callosal thickness at high spatial resolution while removing the variance associated with overall brain size. Within healthy subjects (n=62), and within males (n=28) and females (n=34) separately, we observed significant positive correlations between callosal morphology and intelligence measures (full-scale, performance, and verbal). These relationships were pronounced in posterior callosal sections and were confirmed by permutation testing. Significant negative correlations were absent. Positive associations between intelligence and posterior callosal thickness may reflect a more efficient inter-hemispheric information transfer, positively affecting information processing and integration, and thus intellectual performance. At the same time, regional variations in callosal size might also partly reflect the underlying architecture of topographically connected cortical regions relevant for processing higher-order cognitive information. Our findings emphasize the importance of incorporating posterior (callosal) regions into the theories and models proposed to explain the anatomical substrates of intelligence.

  4. Prosody Meets Syntax: The Role of the Corpus Callosum

    Science.gov (United States)

    Sammler, Daniela; Kotz, Sonja A.; Eckstein, Korinna; Ott, Derek V. M.; Friederici, Angela D.

    2010-01-01

    Contemporary neural models of auditory language comprehension proposed that the two hemispheres are differently specialized in the processing of segmental and suprasegmental features of language. While segmental processing of syntactic and lexical semantic information is predominantly assigned to the left hemisphere, the right hemisphere is…

  5. 儿童伴胼胝体压部可逆性病变的轻度脑炎/脑病患者的临床特征分析%Clinical characteristics in four pediatric patients with mild encephalitis/encephalopathy with a reversible splenial lesion of corpus callosum

    Institute of Scientific and Technical Information of China (English)

    郝小生; 王江涛; 张艳凤; 梁建民

    2015-01-01

    目的 探讨儿童伴胼胝体压部可逆性病变的轻度脑炎/脑病(MERS)患者的临床及影像学特点.方法 对我院2013-2014年诊治的4例MERS患儿的临床资料进行回顾性分析,包括临床表现、神经系统异常体征、实验室检查、磁共振头部平扫(1.5 T)以及治疗和预后情况,并对相关文献进行复习.结果 4例患儿以消化道(3例)或呼吸道(1例)症状起病,以意识障碍(嗜睡3例、昏睡1例)、抽搐(4例)、头痛(1例)为主要症状,神经系统异常体征包括:颈项强直阳性(3例),双侧巴宾斯基征阳性(3例),双侧球结膜水肿(2例).实验室检查:血钠平均131.6 mmol/L,1例脑脊液常规生化异常.病原学检查:2例大便人轮状病毒抗原阳性,2例肺炎支原体抗体阳性.头颅MRI:仅见胼胝体压部可逆性异常信号(斑片状T1WI等或低信号,T2 WI稍高信号,FLAIR稍高信号,DWI高信号,表观弥散系数低信号,边界清晰).常规治疗基础上,加用地塞米松(4例)及丙种球蛋白(3例),1周内临床症状消失,2周内头颅MRI病灶消失.结论 MERS是一种临床-影像学综合征,常急性起病,临床症状轻微,头颅MRI有特征性改变,预后良好.%Objective To investigate the clinical and imaging features of mild encephalitis/encephalopathy with a reversible splenial lesion of corpus callosum (MERS) in children.Methods Four patients of MERS, who were diagnosed and treated in the First Hospital of Jilin University during 2013-2014, were collected retrospectively.Their clinical, laboratory, radiologic data and the related literatures were reviewed.Results Four patients onsetted as gastrointestinal symptom (3 cases) or respiratory (1 case) symptom, in accompany with disturbance of consciousness (3 cases of drowsiness, 1 case of lethargy), convulsions (4 cases), headache (1 case) as the main symptoms.Abnormal neurological signs included positive cervical resistance (3 cases), positive bilateral Babinski sign (3 cases), bilateral

  6. MK-801诱导的精神分裂症小鼠行为学和胼胝体髓鞘的改变%Behavioral alterations and demyelization of the corpus callosum in the mouse model of MK-801 induced schizophrenia

    Institute of Scientific and Technical Information of China (English)

    修芸; 张蕾; 仇玄; 陈林; 卢伟; 彭超; 程国华; 晁凤蕾; 唐勇

    2013-01-01

    Objective To explore the role of white matter injuries in the schizophrenia induced by the NMDA re-ceptor antagonist. Methods Adult male C57BL/6J mice (8 week old) were equally divided into four groups. One group was sub-chronically treated with saline solution, and the other three groups were intraperitoneally treated with MK-801 at dose of 0.025 mg/mL (M1), 0.050 mg/mL (M2) and 0.100 mg/mL (M3) in a volume 10 ml per kilogram body weight. All ani-mals were tested using Morris water maze at the 9th-15th day and using the Hole Board exploration as well as Rota Rod performance tests on the 16th day. The myelin basic protein (MBP) and the ultrastructure of the myelin sheaths in the cor-pus callosum were then examined using immunohistochemical methods, transmission electron microscope technique and stereological methods. Results The repeated sub-chronic MK-801 treatment did not induce impairment of spatial learning and memory in Morris water maze. The MK-801 treatment at 0.25 mg/kg and 1.00 mg/kg but not at 0.50 mg/kg resulted in less exploration to a new environment. The myelin staining with anti-MBP antibody was less intense in all three schizo-phrenic groups when compared to saline control group (P0.05),M1和M3组小鼠较对照组表现出对新环境探索减少的SZ阴性症状;大脑胼胝体区MBP染色M1组(179±10)%、M2组(235±7)%、M3组(152±9)%小鼠较对照组(288±18)%均降低(均P<0.01),其内有髓神经纤维髓鞘出现板层分离、节段性脱髓鞘等病变,M3组小鼠胼胝体内损伤有髓神经纤维比例高于对照组[(22.42±4.24)%vs.(3.84±1.35)%],差异有统计学意义(P<0.01)。结论胼胝体脱髓鞘改变可能是MK-801慢性给药诱导SZ的病因之一。

  7. Interhemispheric Connections between the Primary Visual Cortical Areas via the Anterior Commissure in Human Callosal Agenesis

    OpenAIRE

    van Meer, Nathalie; Houtman, Anne C.; Van Schuerbeek, Peter; Vanderhasselt, Tim; Milleret, Chantal; ten Tusscher, Marcel P.

    2016-01-01

    Aim: In humans, images in the median plane of the head either fall on both nasal hemi-retinas or on both temporal hemi-retinas. Interhemispheric connections allow cortical cells to have receptive fields on opposite sides. The major interhemispheric connection, the corpus callosum, is implicated in central stereopsis and disparity detection in front of the fixation plane. Yet individuals with agenesis of the corpus callosum may show normal stereopsis and disparity vergence. We set out to study...

  8. Reversible Akinetic Mutism after Aneurysmal Subarachnoid Haemorrhage in the Territory of the Anterior Cerebral Artery without Permanent Ischaemic Damage to Anterior Cingulate Gyri

    Directory of Open Access Journals (Sweden)

    François-Xavier Sibille

    2016-01-01

    Full Text Available We report on two cases of transient akinetic mutism after massive subarachnoid haemorrhage due to the rupture of an intracranial aneurysm of the anterior cerebral artery (ACA. In the two cases, vasospasm could not be demonstrated by imaging studies throughout the clinical course. Both patients shared common radiological features: a hydrocephalus due to haemorrhagic contamination of the ventricular system and a mass effect of a subpial hematoma on the borders of the corpus callosum. Patients were also investigated using auditory event-related evoked potentials at acute stage. In contrast to previous observations of akinetic mutism, P300 wave could not be recorded. Both patients had good recovery and we hypothesized that this unexpectedly favourable outcome was due to the absence of permanent structural damage to the ACA territory, with only transient dysfunction due to a reversible mass effect on cingulate gyri.

  9. Alien Hand Sign and Other Cognitive Deficits following Ruptured Aneurysm of the Anterior Communicating Artery

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    Alan J. Parkin

    1991-01-01

    Full Text Available We describe a right-handed patient who suffered a ruptured aneurysm of the anterior communicating artery (ACoA which was clipped successfully. Computerized tomography indicated a low density area in the genu of the corpus callosum and the infero-lateral aspect of the left frontal lobe. On recovery the patient's most notable deficit was the “alien hand sign” whereby the left hand would frequently interfere with the actions of the right hand. Problems in response initiation were also evident. There was significant memory loss and performance was impaired on some tests of frontal lobe function. Discussion centres on the functional locus of the alien hand sign but other aspects of the patient's deficits are also considered.

  10. Old Persian corpus [Dataset

    NARCIS (Netherlands)

    Bavant, M.

    2011-01-01

    XML Old Persian corpus. The corpus is based on publicly available data on the Web. Those data can be traced back to the grammar of Old Persian by Kent (1950). The corpus contains those data and is arranged in a way suitable for corpus searches.

  11. Corpus Linguistics Facilitates English Teaching

    Institute of Scientific and Technical Information of China (English)

    朱思亲

    2014-01-01

    Corpus linguistics has been widely applied in English teaching. Corpus linguistics has changed the way to teach English. The essay discusses two approaches in English teaching based on corpus, corpus-driven approach and corpus-based approach. It finds out that both corpus-driven approach and corpus-based approach facilitate English teaching in their own ways.

  12. Microsurgical anatomy of the anterior cerebral artery in Indian cadavers

    Directory of Open Access Journals (Sweden)

    Shweta Kedia

    2013-01-01

    Full Text Available Background: The microanatomy features of cerebral arteries may be variable and may be different in different ethnic groups. Aim: To study the anterior cerebral artery (ACA anatomy in North-West Indian cadavers. Materials and Methods: Microanatomy features of the ACA were studied in 15 formalin fixed human cadaveric brains under microscope. The outer diameter, length, and number of perforating branches with respective anomalies were measured for each of the following vessels: ACA (proximal A1 segment to distal A2 segment, anterior communicating artery (ACoA, Recurrent artery of Heubner (RAH, and callosomarginal artery and photographed for documentation. Results: The mean length and external diameter of right and left A1 segment was 12.09 mm and 12.0 mm and 2.32 mm and 2.36 mm respectively. Narrowing, duplication, and median ACA were seen in 6.6%, 3.3% and 6.6% of the vessels respectively. Complex ACoA type was seen in 40% cadavers. RAH originated at an average point of 0.2 mm distal to ACoA, but in one cadaver it arose 5 mm proximal to ACoA. Double RAH was found in 26.6%. The course of RAH in relation to A1 was superiorly in 60%, in anteriorly 30% and posteriorly in 10% of cadavers. The orbitofrontal artery (OFA and frontopolar artery (FPA arose from A2 in 83.3% to 40% respectively. The mean distance of OFA and FPA from ACoA was 4.17 mm and 8.5 mm respectively. After giving rise to central, callosal and cortical branches, pericallosal artery terminated near the splenium of the corpus callosum or on the precuneus as the inferomedial parietal artery. Conclusion: Knowledge of the microvascular anatomy is indispensable and it is mandatory to be aware of the possible variations in the anomalies to minimize morbidity.

  13. CALBC silver standard corpus.

    Science.gov (United States)

    Rebholz-Schuhmann, Dietrich; Jimeno Yepes, Antonio José; Van Mulligen, Erik M; Kang, Ning; Kors, Jan; Milward, David; Corbett, Peter; Buyko, Ekaterina; Beisswanger, Elena; Hahn, Udo

    2010-02-01

    The CALBC initiative aims to provide a large-scale biomedical text corpus that contains semantic annotations for named entities of different kinds. The generation of this corpus requires that the annotations from different automatic annotation systems be harmonized. In the first phase, the annotation systems from five participants (EMBL-EBI, EMC Rotterdam, NLM, JULIE Lab Jena, and Linguamatics) were gathered. All annotations were delivered in a common annotation format that included concept identifiers in the boundary assignments and that enabled comparison and alignment of the results. During the harmonization phase, the results produced from those different systems were integrated in a single harmonized corpus ("silver standard" corpus) by applying a voting scheme. We give an overview of the processed data and the principles of harmonization--formal boundary reconciliation and semantic matching of named entities. Finally, all submissions of the participants were evaluated against that silver standard corpus. We found that species and disease annotations are better standardized amongst the partners than the annotations of genes and proteins. The raw corpus is now available for additional named entity annotations. Parts of it will be made available later on for a public challenge. We expect that we can improve corpus building activities both in terms of the numbers of named entity classes being covered, as well as the size of the corpus in terms of annotated documents.

  14. IUS-LEX-CORPUS: CORPUS MYSTICUM

    Directory of Open Access Journals (Sweden)

    Riccardo Pozzo

    2014-01-01

    Full Text Available Sfruttando gli ingenti materiali a disposizione degli studiosi dal 1964 negli archivi, nelle banche dati, nei dizionari e nei lessici d'autore dell'ILIESI-CNR, il contributo considera una serie di momenti nella storia del pensiero, dalla politeía antica al cosmopolitismo moderno, che mettono in risalto le implicazioni filosofiche presenti nella polisemia del trinomio lex-ius-corpus.

  15. Corpus Design for Malay Corpus-based Speech Synthesis System

    Directory of Open Access Journals (Sweden)

    Tian-Swee Tan

    2009-01-01

    Full Text Available Problem statement: Speech corpus is one of the major components in corpus-based synthesis. The quality and coverage in speech corpus will affect the quality of synthesis speech sound. Approach: This study proposes a corpus design for Malay corpus-based speech synthesis system. This includes the study of design criteria in corpus-based speech synthesis, Malay corpus based database design and the concatenation engine in Malay corpus-based synthesis system. A set of 10 millions digital text corpuses for Malay language has been collected from Malay internet news. This text corpus had been analyzed using word frequency count to find out all high frequency words to be used for designing the sentences for speech corpus. Results: Altogether 381 sentences for speech corpus had been designed using 70% of high frequency words from 10 million text corpus. It consists of 16826 phoneme units and the total storage size is 37.6Mb. All the phone units are phonetically transcribed to preserve the phonetic context of its origin that will be used for phonetic context unit. This speech corpus had been labeled at phoneme level and used for variable length continuous phoneme based concatenation. Speech corpus is one of the major components in corpus-based synthesis. The quality and coverage in speech corpus will affect the quality of synthesized speech sound. Conclusion/Recommendation: This study has proposed a platform for designing speech corpus especially for Malay Text to Speech which can be further enhanced to support more coverage and higher naturalness of synthetic speech.

  16. Magnetic resonance imaging and histological studies of corpus callosal and hippocampal abnormalities linked to doublecortin deficiency.

    Science.gov (United States)

    Kappeler, Caroline; Dhenain, Marc; Phan Dinh Tuy, Françoise; Saillour, Yoann; Marty, Serge; Fallet-Bianco, Catherine; Souville, Isabelle; Souil, Evelyne; Pinard, Jean-Marc; Meyer, Gundela; Encha-Razavi, Ferechté; Volk, Andreas; Beldjord, Cherif; Chelly, Jamel; Francis, Fiona

    2007-01-10

    Mutated doublecortin (DCX) gives rise to severe abnormalities in human cortical development. Adult Dcx knockout mice show no major neocortical defects but do have a disorganized hippocampus. We report here the developmental basis of these hippocampal abnormalities. A heterotopic band of neurons was identified starting at E17.5 in the CA3 region and progressing throughout the CA1 region by E18.5. At neonatal stages, the CA1 heterotopic band was reduced, but the CA3 band remained unchanged, continuing into adulthood. Thus, in mouse, migration of CA3 neurons is arrested during development, whereas CA1 cell migration is retarded. On the Sv129Pas background, magnetic resonance imaging (MRI) also suggested abnormal dorsal hippocampal morphology, displaced laterally and sometimes rostrally and associated with medial brain structure abnormalities. MRI and cryosectioning showed agenesis of the corpus callosum in Dcx knockout mice on this background and an intermediate, partial agenesis in heterozygote mice. Wild-type littermates showed no callosal abnormalities. Hippocampal and corpus callosal abnormalities were also characterized in DCX-mutated human patients. Severe hippocampal hypoplasia was identified along with variable corpus callosal defects ranging from total agenesis to an abnormally thick or thin callosum. Our data in the mouse, identifying roles for Dcx in hippocampal and corpus callosal development, might suggest intrinsic roles for human DCX in the development of these structures.

  17. Instrument specific use-dependent plasticity shapes the anatomical properties of the corpus callosum

    DEFF Research Database (Denmark)

    Vollmann, Henning; Ragert, Patrick; Conde, Virginia;

    2014-01-01

    , the amount of IHI in pianists was comparable to that of non-musicians and there was no significant structure-function relationship. Our findings indicate instrument specific use-dependent plasticity in both functional (IHI) and structural (FA) connectivity of motor related brain regions in musicians....

  18. Diffusion tensor imaging, white matter lesions, the corpus callosum, and gait in the elderly

    Science.gov (United States)

    Gait impairment is common in the elderly, especially affected by stroke and white matter hyper intensities found in conventional brain magnetic resonance imaging (MRI). Diffusion tensor imaging (DTI) is more sensitive to white matter damage than conventional MRI. The relationship between DTI measure...

  19. DEVELOPMENTAL HYPOTHYROIDISM INDUCES A NEURONAL HETEROTOPIA IN THE CORPUS CALLOSUM OF THE RAT.

    Science.gov (United States)

    It is well established that severe hypothyroidism leads to profound alterations in brain development and mental retardation. In this study we examined the effect of subtle decreases in maternal thyroid hormones (TH) on brain development in the rat. To induce TH insufficiency pr...

  20. Reduced white matter connectivity in the corpus callosum of children with Tourette syndrome

    DEFF Research Database (Denmark)

    Plessen, Kerstin J; Grüner, Renate; Lundervold, Arvid

    2006-01-01

    , and these anatomical features have been understood to reflect neural plasticity that helps to attenuate the severity of tics. METHOD: CC white matter connectivity, as measured by the Fractional Anisotropy (FA) index from diffusion tensor images, was assessed in 20 clinically well-defined boys with Tourette syndrome...

  1. Reduced white matter connectivity in the corpus callosum of children with Tourette syndrome

    DEFF Research Database (Denmark)

    Plessen, Kerstin J; Grüner, Renate; Lundervold, Arvid;

    2006-01-01

    , and these anatomical features have been understood to reflect neural plasticity that helps to attenuate the severity of tics. METHOD: CC white matter connectivity, as measured by the Fractional Anisotropy (FA) index from diffusion tensor images, was assessed in 20 clinically well-defined boys with Tourette syndrome...... interhemispheric fibers or reduced axonal myelination. FA values did not correlate significantly with the severity of tic symptoms. Group differences in measures of connectivity did not seem to be attributable to the presence of comorbid ADHD or OCD, to medication exposure, or group differences in IQ. CONCLUSION...

  2. Clinical significance of corpus callosum atrophy in a mixed elderly population

    DEFF Research Database (Denmark)

    Ryberg, C.; Rostrup, E.; Stegmann, Mikkel Bille;

    2007-01-01

    ) score, history of depression, geriatric depression scale (GDS) score, subjective gait difficulty, history of falls, walking speed, and total score on the short physical performance battery (SPPB) were analyzed. Significant correlations between CC atrophy and MMSE, SPPB, and walking speed were identified...

  3. Age effects in identifying and localising dichotic stimuli : A corpus callosum deficit?

    NARCIS (Netherlands)

    Gootjes, L; Van Strien, JW; Bouma, A; Bouma, J.M.

    2004-01-01

    In the present study, dichotic listening performance of 31 older adults was compared with performance of 25 younger adults under free and focussed attention conditions. In addition to an age-related general decrease in performance, we observed in the focussed attention condition increased asymmetry

  4. Wnt-induced calcium signaling mediates axon growth and guidance in the developing corpus callosum.

    Science.gov (United States)

    Hutchins, B Ian; Li, Li; Kalil, Katherine

    2012-01-10

    Wnt5a gradients guide callosal axons by repulsion through Ryk receptors in vivo. We recently found that Wnt5a repels cortical axons and promotes axon outgrowth through calcium signaling in vitro. Here, using cortical slices, we show that Wnt5a signals through Ryk to guide and promote outgrowth of callosal axons after they cross the midline. Calcium transient frequencies in callosal growth cones positively correlate with axon outgrowth rates in vitro. In cortical slices, calcium release through inositol 1,4,5-trisphosphate (IP(3)) receptors and calcium entry through transient receptor potential channels modulate axon growth and guidance. Knocking down Ryk inhibits calcium signaling in cortical axons, reduces rates of axon outgrowth subsequent to midline crossing, and causes axon guidance defects. Calcium- and calmodulin-dependent protein kinase II (CaMKII) is required downstream of Wnt-induced calcium signaling for postcrossing callosal axon growth and guidance. Taken together, these results suggest that growth and guidance of postcrossing callosal axons by Wnt-Ryk-calcium signaling involves axon repulsion through CaMKII.

  5. Corpus Annotation for Parser Evaluation

    OpenAIRE

    CARROLL, JOHN; Minnen, Guido; Briscoe, Ted

    1999-01-01

    We describe a recently developed corpus annotation scheme for evaluating parsers that avoids shortcomings of current methods. The scheme encodes grammatical relations between heads and dependents, and has been used to mark up a new public-domain corpus of naturally occurring English text. We show how the corpus can be used to evaluate the accuracy of a robust parser, and relate the corpus to extant resources.

  6. Language Planning: Corpus Planning.

    Science.gov (United States)

    Baldauf, Richard B., Jr.

    1989-01-01

    Focuses on the historical and sociolinguistic studies that illuminate corpus planning processes. These processes are broken down and discussed under two categories: those related to the establishment of norms, referred to as codification, and those related to the extension of the linguistic functions of language, referred to as elaboration. (60…

  7. Tagging the Teleman Corpus

    CERN Document Server

    Brants, T; Brants, Thorsten; Samuelsson, Christer

    1995-01-01

    Experiments were carried out comparing the Swedish Teleman and the English Susanne corpora using an HMM-based and a novel reductionistic statistical part-of-speech tagger. They indicate that tagging the Teleman corpus is the more difficult task, and that the performance of the two different taggers is comparable.

  8. Explorations of Corpus Translation Studies

    Institute of Scientific and Technical Information of China (English)

    何琳琳

    2014-01-01

    Corpus-based translation studies belong to a new translation study paradigm which rose at the beginning of 1990s. The rise of corpus brings the update of research tools and research methods, and lead to the emerging of Corpus Translation Stud-ies. It is necessary to introduce the theory basis of Translational English Corpus and its application in the translation, especially in the science and technology translation. Besides, it makes an analysis and discussion about the potential of Corpus Translation Stud-ies.

  9. Cervicoplastia anterior Anterior cervicoplasty

    Directory of Open Access Journals (Sweden)

    Lucas Gomes Patrocínio

    2004-10-01

    Full Text Available Muitos pacientes buscam correção estética da frouxidão da pele do pescoço, depósito de gordura na região submentoneana ou bandas de platisma. Em grande parte dos casos a ação medial, via cervicoplastia anterior é necessária. OBJETIVO: Demonstrar a casuística e avaliar os resultados e complicações com a técnica de cervicoplastia anterior no Serviço de Otorrinolaringologia da Universidade Federal de Uberlândia. FORMA DE ESTUDO: Relato de série. PACIENTES E MÉTODOS: Quarenta e dois pacientes, entre 39 e 65 anos de idade, sendo 40 (95,2% do sexo feminino e 2 (4,8% do masculino, foram submetidos a cervicoplastia anterior. Retrospectivamente foram avaliados resultados e complicações. RESULTADOS: Destes, 34 apresentaram resultados satisfatórios, 4 apresentaram déficit estético notado somente pelo cirurgião, 3 apresentaram déficit estético notado somente pelo paciente e 1 apresentou déficit estético necessitando cirurgia revisional. Ao estudo fotográfico, todos os pacientes apresentaram melhora do perfil cervical, redução das bandas de platisma e da frouxidão da pele, estabilização da musculatura cervical e acentuação do ângulo cervicomental, em graus variados. Houve complicação em 2 casos (discreto serohematoma e cicatriz um pouco alargada. CONCLUSÃO: A cervicoplastia, associada ou não à tração lateral pela ritidoplastia, é uma técnica que produz resultados satisfatórios na grande maioria dos casos.Many patients look for aesthetic correction of the laxity of neck skin, submandibular fat deposit or platisma bands. In a large part of the cases, medial action, through anterior cervicoplasty is necessary. AIM: To demonstrate the casuistic and to evaluate the results and complications with anterior cervicoplasty technique in the Otorhinolaryngology Service of the Federal University of Uberlândia. STUDY DESIGN: Serie report. PATIENTS AND METHODS: Forty-two patients, between 39 and 65 years of age, being 40 (95

  10. [Ruptured distal anterior cerebral artery aneurysm and diagnostic dyspraxia: a case report].

    Science.gov (United States)

    Wada, M; Kajikawa, H; Fujii, S; Yamamura, K; Kajikawa, M

    1995-04-01

    A case of ruptured distal anterior cerebral artery aneurysm presenting with diagnostic dyspraxia is presented. A 54-year-old female was referred to our hospital with the complaint of sudden onset of headache followed by disturbance of consciousness. CT and MRI revealed subarachnoid hemorrhage with hematomas in the interhemispheric fissure and the supracallosal area, and CAG revealed a left-sided callosomarginal artery aneurysm. During and after hospitalization, she showed diagnostic dyspraxia characterized by behavior of both her hands opposite to what might be expected e.g. when she tried to pick up a bowl, both her hands moved forward and held it at once; she wiped her head and face with toilet paper after urination. At times her hands behaved in opposite ways. For example, while folding cloths, her right hand tended to fold them while the left hand tended to unfold them; when she put on a sweater, as the right hand put it on, the left hand took it off; when she put her shirt into her trousers, one hand pushed it in while the other hand pulled it out. This unusual behavior was considered to be caused by the impairment of the corpus callosum due to compression by the hematoma. It disappeared gradually over a period of one year. Involuntary motor behavior of the left hand while the right hand is in voluntary action is known as diagnostic dyspraxia. Although this symptom has rarely been reported so far in cases of ruptured distal anterior cerebral artery, it may become noticed more frequently through careful observation.

  11. Du corpus au dictionnaire

    CERN Document Server

    Jacquemin, Bernard

    2009-01-01

    In this article, we propose an automatic process to build multi-lingual lexico-semantic resources. The goal of these resources is to browse semantically textual information contained in texts of different languages. This method uses a mathematical model called Atlas s\\'emantiques in order to represent the different senses of each word. It uses the linguistic relations between words to create graphs that are projected into a semantic space. These projections constitute semantic maps that denote the sense trends of each given word. This model is fed with syntactic relations between words extracted from a corpus. Therefore, the lexico-semantic resource produced describes all the words and all their meanings observed in the corpus. The sense trends are expressed by syntactic contexts, typical for a given meaning. The link between each sense trend and the utterances used to build the sense trend are also stored in an index. Thus all the instances of a word in a particular sense are linked and can be browsed easily...

  12. Towards an integrated corpus stylistics

    Directory of Open Access Journals (Sweden)

    McIntyre Dan

    2015-12-01

    Full Text Available Over recent years, the use of corpora in stylistic analysis has grown in popularity. However, questions still remain over the remit of corpus stylistics, its distinction from corpus linguistics generally and its capacity to explain complex stylistic effects. This article argues in favour of an integrated corpus stylistics; that is, an approach to corpus stylistics that integrates it with other stylistic methods and analytical frameworks. I suggest that this approach is needed for two main reasons: (i it is analytically necessary in order to fully explain stylistic effects in texts, and (ii integrating corpus methods with other stylistic tools is what will distinguish corpus stylistics from corpus linguistics. My argument is supported by reference to examples from Mark Haddon’s no vel The Curious Incident of the Dog in the Night-time and the HBO TV series Deadwood. Both these examples rely for their explanation on a combination of corpus stylistic analytical techniques and other stylistic methods of analysis.

  13. [Corpus Hermeticum in history].

    Science.gov (United States)

    Bugaj, R

    2001-01-01

    The originator and founder of hermetism was the mythical Hermes Trismegistos, a deity of the syncretic Hellenistic religion that came into being through the identification of the Greek god Hermes with the Egyptian god Thot. In later Hellenistsic times various hermetic writers considered Hermes Trismegistos to have been a historical personage, a king, prophet and philosopher (physician), as well as author of many widely disseminated writings that made up the so-called Corpus Hermeticum (eighteen separate treatises from the 2nd-4th centuries AD) and the so-called Emerald Table (Tabula Smaragdina). The Corpus Hermeticum is a collection of treatises of a philosophical, religious, theological as well as theosophical nature. The collection played an important role in the development of the philosophy of alchemy and hermetism, and formed the basis for an alchemist philosophy of nature. There are currently two views among scholars on the origins of hermetism. According to one, hermetism derived directly from Egypt, while according to the other it orginated in Greece. In the years 1945-46 a number of hermetic texts forming part of the now famous gnostic "library" were discovered in Nag-Hammadi (Chenosboskion) in Upper Egypt. The Coptic texts from Nag-Hammadi date from the middle of the 4th century AD, and according to experts are translations from the Greek. Some authors (R. Reitzenstein and T. Zieliński) have suggested that along with the appearance in Egypt of the Hermetic Books, attributed to Hermes Trismegistos, there also appeared a new god in Egypt, Poimandres, and a new religion was established, hermetism, which competed for influence with Christianity. The present article discusses the main of the hermetic treatises, including Poimandres, which contains an account of the creation of the world. The article also discusses the reasons for the decline of hermetism as a religion and stresses that in spite of this decline the doctrine managed to survive in the form of

  14. Corpus vitreum, retina og chorioidea biopsi

    DEFF Research Database (Denmark)

    Scherfig, Erik Christian Høegh

    2002-01-01

    oftalmology, biopsy, choroid, corpus vitreum, retina, malignant melanoma, biopsy technic, retinoblastoma......oftalmology, biopsy, choroid, corpus vitreum, retina, malignant melanoma, biopsy technic, retinoblastoma...

  15. Universum Inference and Corpus Homogeneity

    Science.gov (United States)

    Vogel, Carl; Lynch, Gerard; Janssen, Jerom

    Universum Inference is re-interpreted for assessment of corpus homogeneity in computational stylometry. Recent stylometric research quantifies strength of characterization within dramatic works by assessing the homogeneity of corpora associated with dramatic personas. A methodological advance is suggested to mitigate the potential for the assessment of homogeneity to be achieved by chance. Baseline comparison analysis is constructed for contributions to debates by nonfictional participants: the corpus analyzed consists of transcripts of US Presidential and Vice-Presidential debates from the 2000 election cycle. The corpus is also analyzed in translation to Italian, Spanish and Portuguese. Adding randomized categories makes assessments of homogeneity more conservative.

  16. Prefrontal and anterior cingulate cortex abnormalities in Tourette Syndrome: evidence from voxel-based morphometry and magnetization transfer imaging

    Directory of Open Access Journals (Sweden)

    Dengler Reinhard

    2009-05-01

    Full Text Available Abstract Background Pathophysiological evidence suggests an involvement of fronto-striatal circuits in Tourette syndrome (TS. To identify TS related abnormalities in gray and white matter we used optimized voxel-based morphometry (VBM and magnetization transfer imaging (MTI which are more sensitive to tissue alterations than conventional MRI and provide a quantitative measure of macrostructural integrity. Methods Volumetric high-resolution anatomical T1-weighted MRI and MTI were acquired in 19 adult, unmedicated male TS patients without co-morbidities and 20 age- and sex-matched controls on a 1.5 Tesla neuro-optimized GE scanner. Images were pre-processed and analyzed using an optimized version of VBM in SPM2. Results Using VBM, TS patients showed significant decreases in gray matter volumes in prefrontal areas, the anterior cingulate gyrus, sensorimotor areas, left caudate nucleus and left postcentral gyrus. Decreases in white matter volumes were detected in the right inferior frontal gyrus, the left superior frontal gyrus and the anterior corpus callosum. Increases were found in the left middle frontal gyrus and left sensorimotor areas. In MTI, white matter reductions were seen in the right medial frontal gyrus, the inferior frontal gyrus bilaterally and the right cingulate gyrus. Tic severity was negatively correlated with orbitofrontal structures, the right cingulate gyrus and parts of the parietal-temporal-occipital association cortex bilaterally. Conclusion Our MRI in vivo neuropathological findings using two sensitive and unbiased techniques support the hypothesis that alterations in frontostriatal circuitries underlie TS pathology. We suggest that anomalous frontal lobe association and projection fiber bundles cause disinhibition of the cingulate gyrus and abnormal basal ganglia function.

  17. The Bulgarian National Corpus: Theory and Practice in Corpus Design

    Directory of Open Access Journals (Sweden)

    Svetla Koeva

    2012-12-01

    Full Text Available The paper discusses several key concepts related to the development of corpora and reconsiders them in light of recent developments in NLP. On the basis of an overview of present-day corpora, we conclude that the dominant practices of corpus design do not utilise adequately the technologies and, as a result, fail to meet the demands of corpus linguistics, computational lexicology and computational linguistics alike.We proceed to lay out a data-driven approach to corpus design, which integrates the best practices of traditional corpus linguistics with the potential of the latest technologies allowing fast collection, automatic metadata description and annotation of large amounts of data. Thus, the gist of the approach we propose is that corpus design should be centred on amassing large amounts of mono- and multilingual texts and on providing them with a detailed metadata description and high-quality multi-level annotation.We go on to illustrate this concept with a description of the compilation, structuring, documentation, and annotation of the Bulgarian National Corpus (BulNC. At present it consists of a Bulgarian part of 979.6 million words, constituting the corpus kernel, and 33 Bulgarian-X language corpora, totalling 972.3 million words, 1.95 billion words altogether. The BulNC is supplied with a comprehensive metadata description, which allows us to organise the texts according to different principles. The Bulgarian part of the BulNC is automatically processed (tokenised and sentence split and  annotated at several levels: morphosyntactic tagging, lemmatisation, word-sense annotation, annotation of noun phrases and named entities. Some levels of annotation are also applied to the Bulgarian-English parallel corpus with the prospect of expanding multilingual annotation both in terms of linguistic levels and the number of languages for which it is available. We conclude with a brief evaluation of the quality of the corpus and an outline of

  18. DEVELOPING SOFTWARE FOR CORPUS RESEARCH

    Directory of Open Access Journals (Sweden)

    Oliver Mason

    2008-06-01

    Full Text Available Despite the central role of the computer in corpus research, programming is generally not seen as a core skill within corpus linguistics. As a consequence, limitations in software for text and corpus analysis slow down the progress of research while analysts often have to rely on third party software or even manual data analysis if no suitable software is available. Apart from software itself, data formats are also of great importance for text processing. But again, many practitioners are not very aware of the options available to them, and thus idiosyncratic text formats often make sharing of resources difficult if not impossible. This article discusses some issues relating to both data and processing which should aid researchers to become more aware of the choices available to them when it comes to using computers in linguistic research. It also describes an easy way towards automating some common text processing tasks that can easily be acquired without knowledge of actual computer programming.

  19. Normative Data of Corpus Callosal Morphology in a North-West Indian Population- An autopsy and MRI study

    Directory of Open Access Journals (Sweden)

    Tulika Gupta

    2009-01-01

    The values of different CC parameters observed were almost similar to the values reported in the other two Indian studies. However, Indian values were found to be more than the Japanese values for length, height and most of the widths of CC. The length and width of CC were found to be less than those of Caucasian population. Generation of this data will help in comparing the CC structure of different sex and ages, to study variations from the normal and may help in surgical planning. Keywords:autopsy brains; corpus callosum; magnetic resonance imaging; morphometric data.

  20. Lancaster Summer School in Corpus Linguistics

    Directory of Open Access Journals (Sweden)

    Jaka Čibej

    2016-11-01

    Full Text Available Med 12. in 15. julijem je na Univerzi v Lancastru potekala poletna šola korpusnega jezikoslovja Lancaster Summer Schools in Corpus Linguistics and Other Digital Methods. Poletno šolo so organizirali UCREL (University Centre for Computer Corpus Research on Language, ERC (Evropski svet za raziskave – European Research Council, CASS (ESRC Centre for Corpus Approaches to Social Science in ESRC (Economic and Social Research Council, razdeljena pa je bila na šest programov, prilagojenih različnim področjem: Korpusno jezikoslovje za proučevanje jezikov (Corpus Linguistics for Language Studies, Korpusno jezikoslovje za družbene vede (Corpus Linguistics for Social Science, Korpusno jezikoslovje za humanistiko (Corpus Linguistics for Humanities, Statistika za korpusno jezikoslovje (Statistics for Corpus Linguistics, Geografski informacijski sistemi za digitalno humanistiko (Geographical Information Systems for the Digital Humanities in Korpusno podprta obdelava naravnih jezikov (Corpus-based Natural Language Processing.

  1. 33 CFR 165.808 - Corpus Christi Ship Channel, Corpus Christi, TX, safety zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Corpus Christi Ship Channel, Corpus Christi, TX, safety zone. 165.808 Section 165.808 Navigation and Navigable Waters COAST GUARD... § 165.808 Corpus Christi Ship Channel, Corpus Christi, TX, safety zone. (a) The following areas...

  2. 32 CFR 516.20 - Habeas Corpus.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Habeas Corpus. 516.20 Section 516.20 National... RELATIONS LITIGATION Reporting Legal Proceedings to HQDA § 516.20 Habeas Corpus. (a) General. A soldier may file a writ of habeas corpus to challenge his continued custody (usually in a post...

  3. Adults with attention-deficit/hyperactivity disorder - A diffusion-tensor imaging study of the corpus callosum

    DEFF Research Database (Denmark)

    Dramsdahl, Margaretha; Westerhausen, René; Haavik, Jan;

    2012-01-01

    to the control group, whereas the size of the CC did not differ across groups. Our findings thus demonstrate a divergence between microstructural and macrostructural measures in the CC of adults with ADHD. This contrasts with findings in children demonstrating callosal abnormalities in both microstructure...... and macrostructure. Our results may indicate that adults with ADHD in part have succeeded in passing by an earlier developmental delay of the CC, resulting in a normalization of callosal macrostructure into adulthood. However, microstructural differences are still present in adults, which may point to an abnormal...... lateralization in adults with ADHD, or could be a sign of a persisting impairment....

  4. Selectively Reduced Posterior Corpus Callosum Size in a Population-Based Sample of Young Adults Born with Low Birth Weight

    DEFF Research Database (Denmark)

    Aukland, S M; Westerhausen, R; Plessen, K J

    2011-01-01

    BACKGROUND AND PURPOSE: Several studies suggest that VLBW is associated with a reduced CC size later in life. We aimed to clarify this in a prospective, controlled study of 19-year-olds, hypothesizing that those with LBWs had smaller subregions of CC than the age-matched controls, even after...

  5. Application of fused lasso logistic regression to the study of corpus callosum thickness in early Alzheimer's disease.

    Science.gov (United States)

    Lee, Sang H; Yu, Donghyeon; Bachman, Alvin H; Lim, Johan; Ardekani, Babak A

    2014-01-15

    We propose a fused lasso logistic regression to analyze callosal thickness profiles. The fused lasso regression imposes penalties on both the l1-norm of the model coefficients and their successive differences, and finds only a small number of non-zero coefficients which are locally constant. An iterative method of solving logistic regression with fused lasso regularization is proposed to make this a practical procedure. In this study we analyzed callosal thickness profiles sampled at 100 equal intervals between the rostrum and the splenium. The method was applied to corpora callosa of elderly normal controls (NCs) and patients with very mild or mild Alzheimer's disease (AD) from the Open Access Series of Imaging Studies (OASIS) database. We found specific locations in the genu and splenium of AD patients that are proportionally thinner than those of NCs. Callosal thickness in these regions combined with the Mini Mental State Examination scores differentiated AD from NC with 84% accuracy.

  6. Idiom Comprehension Deficits in Relation to Corpus Callosum Agenesis and Hypoplasia in Children with Spina Bifida Meningomyelocele

    Science.gov (United States)

    Huber-Okrainec, J.; Blaser, S.E.; Dennis, M.

    2005-01-01

    Idioms are phrases with figurative meanings that are not directly derived from the literal meanings of the words in the phrase. Idiom comprehension varies with: literality, whether the idiom is literally plausible; compositionality, whether individual words contribute to a figurative meaning; and contextual bias. We studied idiom comprehension in…

  7. Oligodendrocytes in Mouse Corpus Callosum are Coupled Via Gap Junction Channels Formedby Connexin47 and Connexin32

    Institute of Scientific and Technical Information of China (English)

    Marta Maglione; Oliver Tress; Brigitte Haas; Khalad Karram; Jacqueline Trotter; Klaus Willecke; Helmut Kettenmann

    2010-01-01

    已有的超微结构研究显示,白质中的少突胶质细胞和星形胶质细胞之间存在缝隙连接,但少突胶质细胞之间不存在缝隙连接,虽然体外培养的少突胶质细胞可形成功能性缝隙连接.本文研究新生小鼠胼胝体急性脑片中的少突胶质细胞的功能性连接.以全细胞膜片钳技术用生物胞素(一种可渗透的缝隙连接示踪剂)标记少突胶质细胞.平均61个细胞为链霉亲和素-Cy3标记的生物胞素阳性.约77%的连结细胞表达少突胶质细胞标志蛋白CNPase阳性染色,9%表达星形胶质细胞标志蛋白GFAP阳性,14%为CNPase和GFAP阴性.后者的大部分表达Olig2和一些NG2(少突胶质细胞前体细胞的标志物).少突胶质细胞表达Cx47、Cx32和Cx29,星形胶质细胞表达Cx43和Cx30.在Cx47敲除小鼠中,连结细胞的数量减少80%.单独删除Cx32或Cx29并不能显著减少连结细胞的数量,但Cx32/Cx47双缺陷小鼠中没有观察到相互连结的细胞.Cx47敲除完全消除了少突胶质细胞与星形胶质细胞间的耦联.在Cx43敲除动物中,少突胶质细胞-星形胶质细胞间连接仍然存在,但与少突胶质细胞前体细胞间的耦联没有被观察到.在Cx43/Cx30双敲除小鼠中,少突胶质细胞-星形胶质细胞连接几乎不存在.解开连结的少突胶质细胞显示为较高的膜输入电阻.本文认为,白质中的少突胶质细胞依靠Cx47和Cx32的表达形成功能性的合胞体,而星形胶质蛋白缝隙连接蛋白的表达能提升此网络的大小.

  8. Channels of the corpus callosum. Evidence from simple reaction times to lateralized flashes in the normal and the split brain.

    Science.gov (United States)

    Iacoboni, M; Zaidel, E

    1995-06-01

    We studied 75 normal subjects and three commissurotomized patients using unimanual simple reaction times to lateralized flashes as a behavioural estimate of interhemispheric transmission time. Three different versions of the paradigm were performed: (i) the basic task; (ii) a motor task, with an increased complexity of the motor response; and (iii) a visual task, with an increased complexity of the visual stimulus presentation. We tested two hypotheses. First, that the new versions of the simple reaction time task result in shifts in hemispheric specialization for processing motor output (indicated by a main effect of response hand) or visual input (indicated by a main effect of visual field) alone, without affecting callosal transmission. In that case normals and split brain patients would show no significant task by response hand by visual field interaction and no significant task by crossed-uncrossed difference interaction. Secondly, that the new versions of the task affect callosal transfer. In that case, normals, but not split brain patients, would show a significant task by response hand by visual field interaction and a significant task by crossed-uncrossed difference interaction. Results are consistent with the latter hypothesis, showing that the motor task significantly changed the response hand by visual field interaction and the crossed-uncrossed difference, but only in normal subjects, perhaps producing a switch in the callosal channel subserving the interhemispheric transfer.

  9. Sept approches à un corpus

    DEFF Research Database (Denmark)

    La linguistique moderne permet d'analyser la langue parlée dans sa spécificité discursive et situationnelle, syntaxique et lexicale, lui accordant ainsi un statut égal à celui de l'écrit. Le choix de présenter sept approches différentes à un même corpus de base donne lieu d'un côté à une analyse...

  10. MUSAN: A Music, Speech, and Noise Corpus

    OpenAIRE

    Snyder, David; Chen, Guoguo; Povey, Daniel

    2015-01-01

    This report introduces a new corpus of music, speech, and noise. This dataset is suitable for training models for voice activity detection (VAD) and music/speech discrimination. Our corpus is released under a flexible Creative Commons license. The dataset consists of music from several genres, speech from twelve languages, and a wide assortment of technical and non-technical noises. We demonstrate use of this corpus for music/speech discrimination on Broadcast news and VAD for speaker identif...

  11. Enhancing Writing Pedagogy with Learner Corpus Data

    Science.gov (United States)

    Cotos, Elena

    2014-01-01

    Learner corpora have become prominent in language teaching and learning, enhancing data-driven learning (DDL) pedagogy by promoting "learning driven data" in the classroom. This study explores the potential of a local learner corpus by investigating the effects of two types of DDL activities, one relying on a native-speaker corpus (NSC)…

  12. Network Analysis with the Enron Email Corpus

    Science.gov (United States)

    Hardin, J. S.; Sarkis, G.; URC, P. .

    2015-01-01

    We use the Enron email corpus to study relationships in a network by applying six different measures of centrality. Our results came out of an in-semester undergraduate research seminar. The Enron corpus is well suited to statistical analyses at all levels of undergraduate education. Through this article's focus on centrality, students can explore…

  13. Corpus-Based Investigations of Language Use.

    Science.gov (United States)

    Biber, Douglas; And Others

    1996-01-01

    Examines a representative text corpus to gain insights into language structure and use and to open new areas of linguistic inquiry. Various illustrations are presented that provide a glimpse into the value of corpus-based investigations for increasing one's understanding of language use and imparting insights important for designing effective…

  14. Corpus delicti / Jüri Hain

    Index Scriptorium Estoniae

    Hain, Jüri, 1941-

    2001-01-01

    Leonhard Lapini, Sirje Runge, Andres Toltsi ja Mare Vindi 1960ndate lõpu ja 1970ndate alguse tööde näitusest "Corpus in spe" Deco galeriis ning nimetatud kunstnike ja Urmo Rausi uudisloomingu näitusest "Corpus" Tallinna Linnagaleriis

  15. The Multimedia Adult ESL Learner Corpus.

    Science.gov (United States)

    Reder, Stephen; Harris, Kathryn; Setzler, Kristen

    2003-01-01

    Describes what may be the first of a new generation of corpora: the Multimedia Adult ESOL (English as a Second or Other Language) Learner Corpus. The corpus is notable for containing language produced by very low level learners in language classrooms and for the fact that the transcribed language remains linked to video recordings. (Author/VWL)

  16. To Teach Spoken Grammar With Corpus Studies

    Institute of Scientific and Technical Information of China (English)

    CHENG Li

    2016-01-01

    Using scripted materials in spoken language teaching has been challenged in recent years. Accordingly, many scholars have proposed to employ corpus in spoken language teaching. This article proved it is an efficient way to teach spoken grammar by combining scripted materials with authentic materials from corpus.

  17. 外伤性胼胝体损伤的MRI诊断%MRI diagnosis of traumatic injury to corpus cllosum

    Institute of Scientific and Technical Information of China (English)

    朱锡德; 费昶; 衡雪源

    2010-01-01

    Objective To observe the MRI features of traumatic brainin jury to corpus callosum and provide valuable diagnostic information for clinical application. Methods Clinical and radiological data were retrospectively analyzed in 20 MRI-diagnosed patients as having traunmtic brain mjury to corpus callosum. Results Traumatic injury to corpus callosum was rather rare in brain trauma.Most traumatic injury to corpus callosum was non-hemorrhagic and its lesion mainly laid at its body or splenium,sometimes at genu,but rarely at rostrum.Traumatic injury to corpus callosum,being one of the common manifestations in diffuse axonal injury(DAI), could be demonstrated slight hyperintense signal on TI WI and T2WI in early phase.The injury site shrank and liquefaction necrosis appeared in the lesion at the late-mid-injured period with softened focus or gliai scar.MRI showed hyperintense T1 and T2 signal, similar to the signal of the cerebrospinal fluid and demonstrated ventriculomegaly in the corresponding parts.DWI showed hyperintense signal in the lesion in acute and subacutc stages:with time prolonged,isointense signal of the normal brain tissue was found and signal of the cerebrospinal fluid appeared in the present of softened focus.Conclusion Attention should be paid to the traumatic injury to corpus callosum,an indicator for severe trauma or disease.MRI,a sensitive and multi-directional imaging,is superior in detecting non-hemorrhagic injury to the corpus callosum.%[目的] 观察颅脑创伤致胼胝体损伤的MRI表现,为临床提供有价值的诊断信息,提高颅脑创伤的救治水平. 方法 回顾分析临沂市人民医院神经外科自2007年至2009年收治疗的20例MRI证实为胼胝体损伤患者的临床、影像资料,观察其临床表现及MRI各序列特征. 结果 外伤性胼胝体损伤在临床较为少见,以非出血性损伤为主,损伤部位常见于体部及压部,少数位于膝部,嘴部损伤罕见.对于早期非出血

  18. Angiogenesis in the corpus luteum

    Directory of Open Access Journals (Sweden)

    Wulff Christine

    2003-11-01

    Full Text Available Abstract The corpus luteum (CL is a site of intense angiogenesis. Within a short period, this is followed either by controlled regression of the microvascular tree in the non-fertile cycle, or maintenance and stabilisation of the new vasculature a conceptual cycle. The molecular regulation of these diverse aspects is examined. The CL provides a unique model system in which to study the cellular and molecular regulation of angiogenesis. Vascular endothelial growth factor (VEGF has been found to have a major role in the CL. By targeting its action at specific stages of the luteal phase in vivo by antagonists, profound inhibitory effects on luteal angiogenesis and function are observed.

  19. Interactions between Corpus and Lexicon

    DEFF Research Database (Denmark)

    This collection of papers stems from the Fifth Workshop on the Representation and Processing of Sign Languages, held in May 2012 as a satellite to the Language Resources and Evaluation Conference in Istanbul. While there has been occasional attention for sign languages at the main LREC conference......, the main focus there is on spoken languages in their written and spoken forms. This series of workshops, however, offers a forum for researchers focussing on sign languages. For the third time, the workshop had sign language corpora as its main topic. This time, the focus was on the interaction between...... corpus and lexicon. More than half of the papers presented contribute to this topic. Once again, the papers at this workshop clearly identify the potentials of even closer cooperation between sign linguists and sign language engineers, and we think it is events like this that contribute a lot to a better...

  20. Corpus callosotomy in a patient with startle epilepsy.

    Science.gov (United States)

    Gómez, Nicolás Garófalo; Hamad, Ana Paula; Marinho, Murilo; Tavares, Igor M; Carrete, Henrique; Caboclo, Luís Otávio; Yacubian, Elza Márcia; Centeno, Ricardo

    2013-03-01

    Startle epilepsy is a syndrome of reflex epilepsy in which the seizures are precipitated by a sudden and surprising, usually auditory, stimulus. We describe herein a girl who had been suffering with startle-induced seizures since 2 years of age. She had focal, tonic and tonic-clonic seizures, refractory to antiepileptic treatment. Daily tonic seizures led to very frequent falls and morbidity. Neurologically, she had no deficit. Interictal EEG showed slow waves and epileptiform discharges in central and fronto-central regions. Video-polygraphic recordings of seizures, triggered by stimuli, showed generalised symmetric tonic posturing with ictal EEG, characterised by an abrupt and diffuse electrodecremental pattern of fast activity, followed by alpha-theta rhythm superimposed by epileptic discharges predominantly over the vertex and anterior regions. Magnetic resonance imaging showed no abnormalities. Corpus callosotomy was performed when the patient was 17. Since surgery, the patient (one year follow-up) has remained seizure-free. Corpus callosotomy may be considered in patients with startle epilepsy and tonic seizures, in the absence of focal lesions amenable to surgery. [Published with video sequences].

  1. Medroxyprogesterone in Treating Patients With Endometrioid Adenocarcinoma of the Uterine Corpus

    Science.gov (United States)

    2016-03-17

    Endometrial Adenocarcinoma; Endometrial Adenosquamous Carcinoma; Endometrial Endometrioid Adenocarcinoma, Variant With Squamous Differentiation; Recurrent Uterine Corpus Carcinoma; Stage I Uterine Corpus Cancer; Stage II Uterine Corpus Cancer; Stage III Uterine Corpus Cancer; Stage IV Uterine Corpus Cancer

  2. CORPUS AND FREQUENCY GRAMMAR CORPUS VOCABULARY OF THE CHURCH SLAVONIC LANGUAGE AS PART OF THE RUSSIAN NATIONAL CORPUS

    Directory of Open Access Journals (Sweden)

    E. R. Dobrushina

    2015-01-01

    Full Text Available The article describes the current  state of  work on the Corpus of Church Slavonic within the Russian National Corpus. The Corpus is different from the collection of texts by the presence of a special markup (grammatical, structural, metatextual and  the  possibility to  search by this markup. The article considers the content, describes the main genre headings, according to which the texts included in the Corpus are distributed, describes  the principles of the metamarkup that differ from those used in other Corpuses  within the Russian National Corpus. Where necessary, the historical information,  on the basis of  which a certain decision was made, is provided. Since typing search queries on the keyboard presents certain difficulties  for Church Slavonic texts, we offer several options for simplified spelling transmission, which enable a person to enter a query with limited capabilities of a standard keyboard. Finally, the article describes the frequency grammar vocabulary created during the work on the project.

  3. A Corpus-Based Study of Idioms in Academic Speech.

    Science.gov (United States)

    Simpson, Rita; Mendis, Dushyanthi

    2003-01-01

    Addresses the advantages and limitations of a corpus-based approach to researching and teaching idioms in a specific genre by drawing on a specialized corpus of 1.7 million words of academic discourse, the Michigan Corpus of Academic Spoken English. Argues that evidence from such a corpus can be informative for language teachers when the primary…

  4. [Medicine and astrology in Arnau's corpus].

    Science.gov (United States)

    Giralt, Sebastià

    2006-01-01

    The role of astrology in Arnau de Vilanova's medical work is revisited with special attention to the problems of authorship posed by the astrological writings of Arnau's corpus and to their hypothetical chronology.

  5. The Overall Introduction of Corpus Linguistics

    Institute of Scientific and Technical Information of China (English)

    许琳华; 李旭辉; 杨晓伟

    2011-01-01

    @@ i.Preface Corpus can be defined as "…a collection of texts assumed to be represent-ative of a given language put together so that it can be used for linguistic analy-sis" (Tognini - Bonelli 2001 : 2).It is built through collecting authentic lan-guage material.A corpus is a very important basis for language teaching and research.It is also a very important source of information for complication of dictionaries, grammar books and teaching materials.

  6. Integrating corpus consultation in language studies

    OpenAIRE

    Angela Chambers

    2005-01-01

    peer-reviewed Alongside developments in language research, the potential of corpora as a resource in language learning and teaching has been evident to researchers and teachers since the late 1960s. Despite publications which emphasise the benefits of corpus consultation for language learners (Bernardini, 2002; Kennedy & Miceli, 2001), there is little evidence to suggest that direct corpus consultation is coming to be seen as a complement or alternative to consultation of a dictionary, cou...

  7. 77 FR 34034 - Corpus Christi Liquefaction, LLC; Cheniere Corpus Christi Pipeline, L.P.; Notice of Intent To...

    Science.gov (United States)

    2012-06-08

    ... Energy Regulatory Commission Corpus Christi Liquefaction, LLC; Cheniere Corpus Christi Pipeline, L.P.; Notice of Intent To Prepare an Environmental Assessment for the Planned Corpus Christi LNG Terminal and... assessment (EA) that will discuss the environmental impacts of the planned Corpus Christi LNG Terminal...

  8. The Bulgarian-Polish-Russian parallel corpus

    Directory of Open Access Journals (Sweden)

    Maksim Duškin

    2015-11-01

    Full Text Available The Bulgarian-Polish-Russian parallel corpus The Semantics Laboratory Team of Institute of Slavic Studies of Polish Academy of Sciences is planning to begin work on the creation of a Bulgarian-Polish-Russian parallel corpus. The three selected languages are representatives of the main groups of Slavic languages: Bulgarian represents the southern group of Slavic languages, Polish – the western group of Slavic languages, Russian – the eastern group of Slavic languages. Our project will be the first parallel corpus of these three languages. The planned corpus will be based on material, dating from one period (the 20th century and will have a synchronous nature. The project will not constitute the sum of the separate corpora of selected languages. One of the problems with creating multilingual parallel corpora are different proportions of translated texts between the selected languages, for example, Polish literature is often translated into Bulgarian, but not vice versa. Bulgarian, Russian and Polish differ typologically – Bulgarian is an analytic language, Polish and Russian are synthetic. The parallel corpus should have compatible annotation, while taking into account the characteristic features of the selected languages. We hope that the Bulgarian-Polish-Russian parallel corpus will serve as a source of linguistic material of contrastive language studies and may prove to be a big help for linguists, translators, terminologists and students of linguistics. The results of our work will be available on the Internet.

  9. Compiling a Corpus for Teaching Medical Translation

    Directory of Open Access Journals (Sweden)

    Elizabeth de la Teja Bosch

    2014-04-01

    Full Text Available Background: medical translation has countless documentary sources; the major difficulty lies in knowing how to assess them. The corpus is the ideal tool to perform this activity in a rapid and reliable way, and to define the learning objectives based on text typology and oriented towards professional practice.Objective: to compile an electronic corpus that meets the requirements of the professional practice to perform specialized medical translation. Methods: a pedagogical research was conducted in the province of Cienfuegos. The units of analysis involved records from translators of the Provincial Medical Sciences Information Center and specialized translators in this field, who completed a questionnaire to accurately determine their information needs, conditioning the corpus design criteria. The analysis of a set of texts extracted from highly reputable sources led to the text selection and final compilation. Subsequently, the validation of the corpus as a documentary tool for teaching specialized medical translation was performed. Results: there was a concentration of translation assignments in the topics: malignant tumors, hypertension, heart disease, diabetes mellitus and pneumonias. The predominant text typologies were: evaluative and dissemination of current research, with plenty original articles and reviews. The text corpus design criteria were: unannotated, documented, specialized, monitor and comparable. Conclusions: the corpus is a useful tool to show the lexical, terminological, semantic, discursive and contextual particularities of biomedical communication. It allows defining learning objectives and translation problems. Key words: teaching; translating; medicine

  10. Microvascular endothelial cells of the corpus luteum

    Directory of Open Access Journals (Sweden)

    Spanel-Borowski Katherina

    2003-11-01

    Full Text Available Abstract The cyclic nature of the capillary bed in the corpus luteum offers a unique experimental model to examine the life cycle of endothelial cells, involving discrete physiologically regulated steps of angiogenesis, blood vessel maturation and blood vessel regression. The granulosa cells and theca cells of the developing antral follicle and the steroidogenic cells of the corpus luteum produce and respond to angiogenic factors and vasoactive peptides. Following ovulation the neovascularization during the early stages of corpus luteum development has been compared to the rapid angiogenesis observed during tumor formation. On the other end of the spectrum, the microvascular endothelial cells are the first cells to undergo apoptosis at the onset of corpus luteum regression. Important insights on the morphology and function of luteal endothelial cells have been gained from a combination of in vitro and in vivo studies on endothelial cells. Endothelial cells communicate with cells comprising the functional unit of the corpus luteum, i.e., other vascular cells, steroidogenic cells, and immune cells. This review is designed to provide an overview of the types of endothelial cells present in the corpus luteum and their involvement in corpus luteum development and regression. Available evidence indicates that microvascular endothelial cells of the corpus luteum are not alike, and may differ during the process of angiogenesis and angioregression. The contributions of vasoactive peptides generated by the luteal endothelin-1 and the renin-angiotensin systems are discussed in context with the function of endothelial cells during corpus luteum formation and regression. The ability of two cytokines, tumor necrosis factor alpha and interferon gamma, are evaluated as paracrine mediators of endothelial cell function during angioregression. Finally, chemokines are discussed as a vital endothelial cell secretory products that contribute to the recruitment of

  11. Learner-Corpus Interaction: A Locus of Microgenesis in Corpus-Assisted L2 Writing

    Science.gov (United States)

    Park, Kwanghyun

    2012-01-01

    This paper examines the processes through which learners interact with a corpus system and microgenetic development emerges from the interaction. The corpus system described in this paper is capable of retrieving highly relevant textual examples tailored to individual needs. Data were collected from an undergraduate ESL composition course in North…

  12. 77 FR 2448 - Special Local Regulation; HITS Triathlon; Corpus Christi Bayfront, Corpus Christi, TX

    Science.gov (United States)

    2012-01-18

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; HITS Triathlon; Corpus Christi... from portions of the Corpus Christi Bayfront area during the HITS Triathlon on February 18th and 19th, 2012. This Special Local Regulation is necessary to ensure the safety of HITS Triathlon...

  13. INTEGRATING CORPUS CONSULTATION IN LANGUAGE STUDIES

    Directory of Open Access Journals (Sweden)

    Angela Chambers

    2005-05-01

    Full Text Available Alongside developments in language research, the potential of corpora as a resource in language learning and teaching has been evident to researchers and teachers since the late 1960s. Despite publications which emphasise the benefits of corpus consultation for language learners (Bernardini, 2002; Kennedy & Miceli, 2001, there is little evidence to suggest that direct corpus consultation is coming to be seen as a complement or alternative to consultation of a dictionary, course book, or grammar by the majority of learners. There is thus a need for research to underpin the integration of corpora and concordancing in the language-learning environment.This study begins with an account of published research relating to course design and structure in the area of corpus consultation by language learners. The focus then narrows to the initial training of learners in corpus consultation, using as an example a course involving undergraduate students on several language degree programmes. The results of the students' consultation of the corpora are examined, including choice of search word(s, analytical skills, the problems encountered, and their evaluation of the activity. The results reveal how corpus consultation can complement traditional language-learning resources, while also raising questions concerning its integration in the language-learning environment.

  14. KoralQuery -- A General Corpus Query Protocol

    DEFF Research Database (Denmark)

    Bingel, Joachim; Diewald, Nils

    2015-01-01

    The task-oriented and format-driven development of corpus query systems has led to the creation of numerous corpus query languages (QLs) that vary strongly in expressiveness and syntax. This is a severe impediment for the interoperability of corpus analysis systems, which lack a common protocol....... In this paper, we present KoralQuery, a JSON-LD based general corpus query protocol, aiming to be independent of particular QLs, tasks and corpus formats. In addition to describing the system of types and operations that KoralQuery is built on, we exemplify the representation of corpus queries in the serialized...

  15. A Corpus for Evidence Based Medicine Summarisation

    Directory of Open Access Journals (Sweden)

    Diego Mollá Aliod

    2012-09-01

    Full Text Available Background Automated text summarisers that find the best clinical evidence reported in collections of medical literature are of potential benefit for the practice of Evidence Based Medicine (EBM. Research and development of text summarisers for EBM, however, is impeded by the lack of corpora to train and test such systems. Aims To produce a corpus for research in EBM summarisation. Method We sourced the “Clinical Inquiries” section of the Journal of Family Practice (JFP and obtained a sizeable sample of questions and evidence based summaries. We further processed the summaries by combining automated techniques, human annotations, and crowdsourcing techniques to identify the PubMed IDs of the references. Results The corpus has 456 questions, 1,396 answer components, 3,036 answer justifications, and 2,908 references. Conclusion The corpus is now available for the research community at http://sourceforge.net/projects/ebmsumcorpus.

  16. Corpus-Assisted Creative Writing: Introducing Intermediate Italian Learners to a Corpus as a Reference Resource

    Directory of Open Access Journals (Sweden)

    Claire Kennedy

    2010-02-01

    Full Text Available In much of the literature on the exploitation of corpora for language learning, the learners are viewed as researchers, who formulate and test their own hypotheses about language use. Having identified difficulties encountered in corpus investigations by our intermediate-level students of Italian in a previous study, we have designed a semester-long apprenticeship in corpus use which does not demand of them the high level of language proficiency, attention to detail in observation, and logical rigour that we consider necessary for rewarding work in the learner-as-researcher role. Instead, we introduce a corpus initially as an aid to the imagination in writing, and then to achieving accuracy through specific grammatical problem solving. We see this as the groundwork for subsequent development of the students’ research skills with corpus data. This paper describes the approach we have adopted to the corpus apprenticeship and reports on an evaluation of its effectiveness through case studies of three students and their use of a corpus and bilingual dictionary as reference resources when writing. Drawing on insights from the case studies, we outline a working definition of corpus-consultation literacy for our learning context and identify some refinements to be made to our apprenticeship.

  17. arTenTen: Arabic Corpus and Word Sketches

    Directory of Open Access Journals (Sweden)

    Tressy Arts

    2014-12-01

    The article also presents the ‘sketch grammar’ (the basis for the word sketches in detail, describes the process of building and processing the corpus, and considers the role of the corpus in additional research on Arabic.

  18. CONGENITAL ANTERIOR TIBIOFEMURAL SUBLUXATION

    Directory of Open Access Journals (Sweden)

    A. Shahla

    2008-06-01

    Full Text Available Congenital anterior tibiofemoral subluxation is an extremely rare disorder. All reported cases accompanied by other abnormalities and syndromes. A 16-year-old high school girl referred to us with bilateral anterior tibiofemoral subluxation as the knees were extended and reduced at more than 30 degrees flexion. Deformities were due to tightness of the iliotibial band and biceps femuris muscles and corrected by surgical release. Associated disorders included bilateral anterior shoulders dislocation, short metacarpals and metatarsals, and right calcaneuvalgus deformity.

  19. A Massive Chinese Floral Corpus Completed

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Through the efforts of several generations of Chinese botanists over the past 50years, a massive 80-volume corpus (in 126 books) on China's flora,Flora Reipublicae Popularis Sinicae (Chinese edition), has finally been completed. This was announced at a press meeting on March 31 in Beijing.

  20. Rheumatic diseases in the Corpus Hippocraticum

    Directory of Open Access Journals (Sweden)

    G. Squillace

    2011-09-01

    Full Text Available Medecine of V and IV centuries B.C. attested in the Corpus Hippocraticum ascribes all diseases to the rheuma, i.e. the flux of humours into the body. This flux produces not only the rise of cold, hoarsness, cough, reddenings, dropsy, but also arthritis, sciatica, gout.

  1. Two directions of change in one corpus

    DEFF Research Database (Denmark)

    Jensen, Marie Møller

    2015-01-01

    Cheshire et al. (2005) argue that different levels of language do not necessarily follow the same patterns of change over time. In an attempt to test this prediction, this article reports on a comparison between two quantitative corpus studies of Tyneside English which are partly based on the same...

  2. Inflation Metaphor in the TIME Magazine Corpus

    Science.gov (United States)

    Hu, Chunyu; Liu, Huijie

    2016-01-01

    A historical perspective on economy metaphor can shed new lights on economic thoughts. Based on the TIME Magazine Corpus (TMC), this paper investigates inflation metaphor over 83 years and compares findings against the economic data over the relatively corresponding period. The results show how inflation, an abstract concept and a normal economic…

  3. 38 CFR 3.263 - Corpus of estate; net worth.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Corpus of estate; net....263 Corpus of estate; net worth. (a) General. The following rules are for application in determining the corpus of estate of a parent where dependency is a factor under § 3.250, and the net worth of...

  4. 33 CFR 110.75 - Corpus Christi Bay, Tex.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Corpus Christi Bay, Tex. 110.75... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.75 Corpus Christi Bay, Tex. (a) South area. Southward of... said breakwater; and eastward of the Corpus Christi sea wall....

  5. Using a Corpus in a 300-Level Spanish Grammar Course

    Science.gov (United States)

    Benavides, Carlos

    2015-01-01

    The present study examined the use and effectiveness of a large corpus--the Corpus del Español (Davies, 2002)--in a 300-level Spanish grammar university course. Students conducted hands-on corpus searches with the goal of finding concordances containing particular types of collocations (combinations of words that tend to co-occur) and tokens (any…

  6. An annotated corpus for the analysis of VP ellipsis

    NARCIS (Netherlands)

    Bos, Johan; Spenader, J.

    2011-01-01

    Verb Phrase Ellipsis (VPE) has been studied in great depth in theoretical linguistics, but empirical studies of VPE are rare. We extend the few previous corpus studies with an annotated corpus of VPE in all 25 sections of the Wall Street Journal corpus (WSJ) distributed with the Penn Treebank. We an

  7. MEANTIME, the NewsReader Multilingual Event and Time Corpus

    NARCIS (Netherlands)

    Minard, A.-L.; Speranza, M; Urizar, R.; Altuna, B.; Erp, van M.G.J.; Schoen, A.M.; Son, van C.M.

    2016-01-01

    In this paper, we present the NewsReader MEANTIME corpus, a semantically annotated corpus of Wikinews articles. The corpus consists of 480 news articles, i.e. 120 English news articles and their translations in Spanish, Italian, and Dutch. MEANTIME contains annotations at different levels. The docum

  8. The Nordic Dialect Corpus – a joint research infrastructure

    Directory of Open Access Journals (Sweden)

    Janne Bondi Johannessen

    2011-06-01

    Full Text Available The paper describes the Nordic Dialect Corpus as of June 2010. The corpus is a tool that combines a number of useful features that together makes it a unique and very advanced resource for researchers of many fields of language search. The corpus is web-based and features full audio-visual representation linked to transcriptions and translations.

  9. Concept annotation in the CRAFT corpus

    Directory of Open Access Journals (Sweden)

    Bada Michael

    2012-07-01

    Full Text Available Abstract Background Manually annotated corpora are critical for the training and evaluation of automated methods to identify concepts in biomedical text. Results This paper presents the concept annotations of the Colorado Richly Annotated Full-Text (CRAFT Corpus, a collection of 97 full-length, open-access biomedical journal articles that have been annotated both semantically and syntactically to serve as a research resource for the biomedical natural-language-processing (NLP community. CRAFT identifies all mentions of nearly all concepts from nine prominent biomedical ontologies and terminologies: the Cell Type Ontology, the Chemical Entities of Biological Interest ontology, the NCBI Taxonomy, the Protein Ontology, the Sequence Ontology, the entries of the Entrez Gene database, and the three subontologies of the Gene Ontology. The first public release includes the annotations for 67 of the 97 articles, reserving two sets of 15 articles for future text-mining competitions (after which these too will be released. Concept annotations were created based on a single set of guidelines, which has enabled us to achieve consistently high interannotator agreement. Conclusions As the initial 67-article release contains more than 560,000 tokens (and the full set more than 790,000 tokens, our corpus is among the largest gold-standard annotated biomedical corpora. Unlike most others, the journal articles that comprise the corpus are drawn from diverse biomedical disciplines and are marked up in their entirety. Additionally, with a concept-annotation count of nearly 100,000 in the 67-article subset (and more than 140,000 in the full collection, the scale of conceptual markup is also among the largest of comparable corpora. The concept annotations of the CRAFT Corpus have the potential to significantly advance biomedical text mining by providing a high-quality gold standard for NLP systems. The corpus, annotation guidelines, and other associated resources are

  10. 33 CFR 334.800 - Corpus Christi Bay, Tex.; seaplane restricted area, U.S. Naval Air Station, Corpus Christi.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Corpus Christi Bay, Tex.; seaplane restricted area, U.S. Naval Air Station, Corpus Christi. 334.800 Section 334.800 Navigation and... RESTRICTED AREA REGULATIONS § 334.800 Corpus Christi Bay, Tex.; seaplane restricted area, U.S. Naval...

  11. Applying corpus methods to written academic texts: Explorations of MICUSP

    Directory of Open Access Journals (Sweden)

    Ute Römer

    2010-08-01

    Full Text Available Based on explorations of the Michigan Corpus of Upper-level Student Papers (MICUSP, the present paper provides an introduction to the central techniques in corpus analysis, including the creation and examination of word lists, keyword lists, concordances, and cluster lists. It also presents a MICUSP-based case study of the demonstrative pronoun this and the distribution and use of its attended and unattended forms in different disciplinary subsets of the corpus. The paper aims to demonstrate how corpus linguistics and corpus methods can contribute to writing research and provide fruitful insights into student academic writing.

  12. Corpus Christi, Nueces, and Aransas Bays

    Science.gov (United States)

    Handley, Lawrence R.; Spear, Kathryn A.; Eleonor Taylor,; Thatcher, Cindy

    2015-01-01

    Corpus Christi Bay and Nueces Bay comprise the middle estuarine portion of Texas’ Coastal Bend region (Figure 1; Burgan and Engle, 2006). Aransas Bay is part of the upper estuarine portion of the region. These bays make up part of the Coastal Bend Bays and Estuaries Program, one of the many estuarine areas in the U.S. Environmental Protection Agency’s National Estuary Program (Holt, 1998). The Coastal Bend region is sub-humid and sub-tropical. Summers are long, hot, and humid, and winters are short and mild. The landscape around the estuaries is dominated by row crops, pastures, and brushy rangeland (Handley and others, 2007). The Nueces River, along with other smaller rivers and creeks, provides freshwater inflow—along with essential nutrients and sediment— into Nueces Bay, which feeds into Corpus Christi Bay (Holt, 1998). Freshwater inflow into the Aransas Bay comes from Mission River, Aransas River, and Copano Creek. The region is relatively dry otherwise and prone to droughts. Corpus Christi receives an average of 76.2 cm (30 in) of rain annually; evaporation usually exceeds 177.8 cm (70 in) (Holt, 1998; Handley and others, 2007). The San Antonio-Nueces Coastal Basin drains into Aransas Bay. The Nueces River basin covers 43,253 km2 (16,700 miles2 ), from northwest of San Antonio, flowing southeast to where it drains into Nueces and Corpus Christi Bays (Holt, 1998). The Nueces-Rio Grande basin covers approximately 18,648 1 U.S. Geological Survey National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506 2 Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, Texas 78412 2 km2 (7,200 miles2 ) and flows partially into Corpus Christi Bay (as well as the upper Laguna Madre). The inflow from Nueces River has declined by approximately 20 percent over the past several decades, partly due to construction of lakes and reservoirs, particularly Lake Corpus Christi

  13. Anterior Cruciate Ligament (ACL) Injuries

    Science.gov (United States)

    ... Week of Healthy Breakfasts Shyness Anterior Cruciate Ligament (ACL) Injuries KidsHealth > For Teens > Anterior Cruciate Ligament (ACL) ... and Recovery Coping With an ACL Injury About ACL Injuries A torn anterior cruciate ligament (ACL) is ...

  14. Corpus-based Studies on Nursing Textbooks

    Directory of Open Access Journals (Sweden)

    Alif Fairus Nor Mohamad

    2013-07-01

    Full Text Available English for Specific Purposes (ESP educators often face dilemma in deciding what lexical items to teach their students. In the field of English for Nursing Purposes (ENP, there is no exception on this issue as well. Only by analyzing the nursing corpus made up of essential core textbooks that can provide better insights and guide to both nursing students and educators. This research aims to highlight the 2,000 most frequently used nursing words across the core textbooks of nursing and to profile the types of ‘low frequency’ lexis which comprise the nursing corpus in terms of the General Service List (GSL and Academic Word List (AWL lexis coverage. By knowing the frequently used nursing words would further reduce students’ reading deficiency if the students use the 2000-word list.

  15. Bayesian Stratified Sampling to Assess Corpus Utility

    CERN Document Server

    Hochberg, J; Thomas, T; Hall, S; Hochberg, Judith; Scovel, Clint; Thomas, Timothy; Hall, Sam

    1998-01-01

    This paper describes a method for asking statistical questions about a large text corpus. We exemplify the method by addressing the question, "What percentage of Federal Register documents are real documents, of possible interest to a text researcher or analyst?" We estimate an answer to this question by evaluating 200 documents selected from a corpus of 45,820 Federal Register documents. Stratified sampling is used to reduce the sampling uncertainty of the estimate from over 3100 documents to fewer than 1000. The stratification is based on observed characteristics of real documents, while the sampling procedure incorporates a Bayesian version of Neyman allocation. A possible application of the method is to establish baseline statistics used to estimate recall rates for information retrieval systems.

  16. An Automatic Collocation Extraction from Arabic Corpus

    Directory of Open Access Journals (Sweden)

    Abdulgabbar M. Saif

    2011-01-01

    Full Text Available Problem statement: The identification of collocations is very important part in natural language processing applications that require some degree of semantic interpretation such as, machine translation, information retrieval and text summarization. Because of the complexities of Arabic, the collocations undergo some variations such as, morphological, graphical, syntactic variation that constitutes the difficulties of identifying the collocation. Approach: We used the hybrid method for extracting the collocations from Arabic corpus that is based on linguistic information and association measures. Results: This method extracted the bi-gram candidates of Arabic collocation from corpus and evaluated the association measures by using the n-best evaluation method. We reported the precision values for each association measure in each n-best list. Conclusion: The experimental results showed that the log-likelihood ratio is the best association measure that achieved highest precision.

  17. A ROUGH GUIDE TO DOING CORPUS STYLISTICS

    Directory of Open Access Journals (Sweden)

    Tania M. G. Shepherd

    2015-11-01

    Full Text Available This article has two main purposes. The first is to provide a short panorama of existing trends within computer-assisted stylistics. The second is to analyse a prize winning novel by English writer Julian Barnes, by resorting to the tenets and working tools of one of the newest branch of Stylistics, the so-called Corpus stylistics. To this end, the article starts by looking at various attempts at defining what style is and their implications to the definition of the discipline known as Stylistics. Then the paper presents recent work within the field of Corpus stylistics, as it describes the uses of computational tools as part of the stylistician tool kit. Finally, the paper provides a variety of ways with which a literary work may be approached digitally with a view to showing how computational tools can aid the stylistician in acts of interpretation.

  18. Corpus-Based Word Sense Disambiguation

    CERN Document Server

    Fujii, A

    1998-01-01

    Resolution of lexical ambiguity, commonly termed ``word sense disambiguation'', is expected to improve the analytical accuracy for tasks which are sensitive to lexical semantics. Such tasks include machine translation, information retrieval, parsing, natural language understanding and lexicography. Reflecting the growth in utilization of machine readable texts, word sense disambiguation techniques have been explored variously in the context of corpus-based approaches. Within one corpus-based framework, that is the similarity-based method, systems use a database, in which example sentences are manually annotated with correct word senses. Given an input, systems search the database for the most similar example to the input. The lexical ambiguity of a word contained in the input is resolved by selecting the sense annotation of the retrieved example. In this research, we apply this method of resolution of verbal polysemy, in which the similarity between two examples is computed as the weighted average of the simi...

  19. DEVELOPING AN ONLINE CORPUS OF FORMOSAN LANGUAGES

    Directory of Open Access Journals (Sweden)

    Li-May Sung

    2008-12-01

    Full Text Available Information technologies have now matured to the point of enabling researchers to create a repository of language resources, especially for those languages facing the crisis of endangerment. The development of an online platform of corpora, made possible by recent advances in data storage, character-encoding and web technology, has profound consequences for the accessibility, quantity, quality and interoperability of linguistic field data. This is of particular significance for Formosan languages in Taiwan, many of which are on the verge of extinction. As a response to the recognition of this burgeoning problem, the key objectives of the establishment of the NTU Corpus of Formosan Languages aim to document and thus preserve valuable linguistic data, as well as relevant ethnological and cultural information. This paper will introduce some of the theoretical bases behind this initiative, as well as the procedures, transcription conventions, database normalization, in-house system and three special features in the creation of this corpus.

  20. MR-billeddiagnostik af corpus pineale

    DEFF Research Database (Denmark)

    Langevad, Line; Gøbel Madsen, Camilla; Siebner, Hartwig R.;

    2014-01-01

    Tilgængeligheden af højopløselige MR-teknikker har ført til større opmærksomhed på og nye spørgsmål vedrørende corpus pineales (CP) funktion og kliniske betydning. Dertil kommer en stigende interesse for hormonet melatonins kliniske betydning og relation til forandringer i CP. I denne statusartikel...

  1. USING CORPUS DATA IN RUSSIAN LANGUAGE CLASSROOM

    Directory of Open Access Journals (Sweden)

    A. I. Levinson

    2015-01-01

    Full Text Available Corpora have not yet become an everyday tool of a Russian language teacher in Russia. My goal is to demonstrate a wide range of usagebased approaches which can be applied in the teaching of L1 to children. I present the benefits of exploiting Russian National Corpus as a valuable pedagogical resource, as well as obstacles which can be caused by using data-based teaching methods.

  2. Conditional Sentences: ELT typology and corpus evidence.

    OpenAIRE

    Gabrielatos, Costas

    2003-01-01

    This paper presents the findings of a pilot study examining the representation of the typology of conditional sentences presented in English language teaching (ELT) materials (coursebooks and grammars) in a random sample of 1,000 conditional sentences from the British National Corpus. The if-clause and main clause of the conditional sentences in the sample was annotated for the form of the main verb (particularly tense and aspect), the modal auxiliaries and other lexis expressing modality, ti...

  3. A metaphor corpus in business press headlines

    Directory of Open Access Journals (Sweden)

    Honesto Herrera Soler

    2008-04-01

    Full Text Available In linguistics a corpus typically involves a finite body of texts which are considered to be representative of a particular variety of language at a specific time (McEnery & Wilson, 2001. Those are the assumptions we have had in mind in this metaphor corpus based on business press headlines. Our body of texts is a finite number of headlines drawn from the specific field of the business sections of three newspapers: Financial Times, El País and El Mundo, published over a period running from January to July 2003. Compiling a small corpus of non-literal instantiations as different authors have done (Cortés de los Ríos, 2001; Kövecses, 2002; Charteris-Black, 2003; Koller, 2004; Deignan, 2005; and others will enable us first to identify whether the contextual meaning of a word or a multiword unit of headline contrasts with its basic meaning and whether the contextual meaning can be understood by comparison with that basic meaning, and then to categorize, both in the Spanish and in the British press, the different linguistic realizations of a headline in terms of their syntactic structure, metaphor foci and source domains.

  4. Named Entity Recognition Using Web Document Corpus

    Directory of Open Access Journals (Sweden)

    Wahiba Ben Abdessalem Karaa

    2011-02-01

    Full Text Available This paper introduces a named entity recognition approach in textual corpus. This Named Entity (NE can be a named: location, person, organization, date, time, etc., characterized by instances. A NE isfound in texts accompanied by contexts: words that are left or right of the NE. The work mainly aims at identifying contexts inducing the NE’s nature. As such, The occurrence of the word "President" in atext, means that this word or context may be followed by the name of a president as President "Obama". Likewise, a word preceded by the string "footballer" induces that this is the name of afootballer. NE recognition may be viewed as a classification method, where every word is assigned to a NE class, regarding the context. The aim of this study is then to identify and classify the contexts that are most relevant to recognize aNE, those which are frequently found with the NE. A learning approach using training corpus: web documents, constructed from learning examples is then suggested. Frequency representations andmodified tf-idf representations are used to calculate the context weights associated to context frequency, learning example frequency, and document frequency in the corpus.

  5. Anterior cervical plating

    Directory of Open Access Journals (Sweden)

    Gonugunta V

    2005-01-01

    Full Text Available Although anterior cervical instrumentation was initially used in cervical trauma, because of obvious benefits, indications for its use have been expanded over time to degenerative cases as well as tumor and infection of the cervical spine. Along with a threefold increase in incidence of cervical fusion surgery, implant designs have evolved over the last three decades. Observation of graft subsidence and phenomenon of stress shielding led to the development of the new generation dynamic anterior cervical plating systems. Anterior cervical plating does not conclusively improve clinical outcome of the patients, but certainly enhances the efficacy of autograft and allograft fusion and lessens the rate of pseudoarthrosis and kyphosis after multilevel discectomy and fusions. A review of biomechanics, surgical technique, indications, complications and results of various anterior cervical plating systems is presented here to enable clinicians to select the appropriate construct design.

  6. The Significance of Self-built Learners’ Written English Corpus

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>Researchers have reached an agreement that corpus exerts an important role in the English teaching and learning,and several learners’ corpus have been established.This paper aims to discuss the necessity and significance of establishing self-built learners’ written English corpus in the hope that teachers and learners will get to know it and use it effectively in their practice.

  7. Neuropsychological performance and corpus callosum abnormalities in adolescents with history of permaturity / Rendimiento neuropsicológico y anormalidades del cuerpo calloso en adolescentes con antecedentes de prematuridad

    OpenAIRE

    Narberhaus, Ana

    2007-01-01

    1. INTRODUCCIÓNLa definición de prematuro es la de recién nacido de edad gestacional inferior a 37 semanas (American Academy of Pediatrics y American College of Obstetrics and Gynecology, 2002). En relación al peso se utilizan con frecuencia las categorías: bajo peso (< 2500g), muy bajo peso (< 1500g) y extremadamente bajo peso (< 1000g) (Picard et al. 2000).En la actualidad, la tasa de partos prematuros en España se sitúa entorno al 8% (Instituto Nacional de Estadística de España: www.se-neo...

  8. What is the role of the corpus callosum in intermanual transfer of motor skills? A study of three cases with callosal pathology

    NARCIS (Netherlands)

    Thut, G; Halsband, U; Regard, M; Mayer, E; Leenders, KL; Landis, T

    1997-01-01

    Intermanual transfer for a skilled motor task was studied in two patients with total callosal agenesis, and one with an acquired partial callosal lesion and clinical evidence for disturbed transfer of motor signals. Patients had to draw meaningless figures with one upper extremity (original learning

  9. MRI study on corpus callosum atrophy in alzheimer disease%Alzheimer病胼胝体萎缩的MRI定量研究

    Institute of Scientific and Technical Information of China (English)

    张雪宁; 陈希颖

    2002-01-01

    目的:评价胼胝体面积测量对诊断Alzheimer病(Alzheimer disease,AD)的价值.方法:14名AD患者和20名年龄、性别、受教育程度相匹配的正常对照,进行MRI扫描并全部行简易精神状态量表(MMSE)检查.结果:AD组胼胝体面积区域性减少,胼胝体萎缩与AD的认知功能损害显著相关.结论:胼胝体面积的测量可以有助于AD的明确诊断.

  10. Inferring cultural models from corpus data

    DEFF Research Database (Denmark)

    Jensen, Kim Ebensgaard

    2015-01-01

    developed methods of inferring cultural models from observed behavior – in particular observed verbal behavior (including both spoken and written language). While there are plenty of studies of the reflection of cultural models in artificially generated verbal behavior, not much research has been made...... of constructional discursive behavior, the present paper offers a covarying collexeme analysis of the [too ADJ to V]-construction in the Corpus of Contemporary American English. The purpose is to discover the extent to which its force-dynamic constructional semantics interacts with cultural models. We focus...

  11. Corpus & Its Application in Language Teaching

    Institute of Scientific and Technical Information of China (English)

    蔺华国; 王璇

    2004-01-01

    Taking advantage of vast electronic text resources, the corpus-based approach has contributed a lot to linguistic research. It can be applied to almost all areas of investigations in linguistics (Biber, Conrad and Reppen, 1998) . At the same time the role of corpora in the language classroom remains a great controversy. Some linguists believe that corpora are of great help to the language teachers whereas some others hold a negative view on its application to language teaching. As this argument is still under debate , many language teachers are applying corpora to their own teaching and this is the best way to evaluate the adoption of corpora in language classroom.

  12. Two directions of change in one corpus

    DEFF Research Database (Denmark)

    Jensen, Marie Møller

    2015-01-01

    Cheshire et al. (2005) argue that different levels of language do not necessarily follow the same patterns of change over time. In an attempt to test this prediction, this article reports on a comparison between two quantitative corpus studies of Tyneside English which are partly based on the same...... forms. The second study was a study of seven morphosyntactic variables based on data collected in the 1960s, 1994 and 2007-2009. This study found that the variables under investigation were either stable over time or used more frequently in the most recent data. Thus, the comparison of the two studies...... at a time when this area is undergoing vast changes....

  13. Corpus-Assisted Creative Writing: Introducing Intermediate Italian Learners to a Corpus as a Reference Resource

    Science.gov (United States)

    Kennedy, Claire; Miceli, Tiziana

    2010-01-01

    In much of the literature on the exploitation of corpora for language learning, the learners are viewed as researchers, who formulate and test their own hypotheses about language use. Having identified difficulties encountered in corpus investigations by our intermediate-level students of Italian in a previous study, we have designed a…

  14. Creating a Live, Public Short Message Service Corpus: The NUS SMS Corpus

    CERN Document Server

    Chen, Tao

    2011-01-01

    Short Message Service (SMS) messages are largely sent directly from one person to another from their mobile phones. They represent a means of personal communication that is an important communicative artifact in our current digital era. As most existing studies have used private access to SMS corpora, comparative studies using the same raw SMS data has not been possible up to now. We describe our efforts to collect a public SMS corpus to address this problem. We use a battery of methodologies to collect the corpus, paying particular attention to privacy issues to address contributors’ concerns. Our live project collects new SMS message submissions, checks their quality and adds the valid messages, releasing the resultant corpus as XML and as SQL dumps, along with corpus statistics, every month. We opportunistically collect as much metadata about the messages and their sender as possible, so as to enable different types of analyses. To date, we have collected about 60,000 messages, focusing on English and...

  15. Temporal Expressions in Polish Corpus KPWr

    Directory of Open Access Journals (Sweden)

    Jan Kocoń

    2015-12-01

    Full Text Available Temporal Expressions in Polish Corpus KPWr This article presents the result of the recent research in the interpretation of Polish expressions that refer to time. These expressions are the source of information when something happens, how often something occurs or how long something lasts. Temporal information, which can be extracted from text automatically, plays significant role in many information extraction systems, such as question answering, discourse analysis, event recognition and many more. We prepared PLIMEX — a broad description of Polish temporal expressions with annotation guidelines, based on the state-of-the-art solutions for English, mainly TimeML specification. We also adapted the solution to capture the local semantics of temporal expressions, called LTIMEX. Temporal description also supports further event identification and extends event description model, focusing at anchoring events in time, ordering events and reasoning about the persistence of events. We prepared the specification, which is designed to address these issues and we annotated all documents in Polish Corpus of Wroclaw University of Technology (KPWr using our annotation guidelines.

  16. Towards an event annotated corpus of Polish

    Directory of Open Access Journals (Sweden)

    Michał Marcińczuk

    2015-12-01

    Full Text Available Towards an event annotated corpus of Polish The paper presents a typology of events built on the basis of TimeML specification adapted to Polish language. Some changes were introduced to the definition of the event categories and a motivation for event categorization was formulated. The event annotation task is presented on two levels – ontology level (language independent and text mentions (language dependant. The various types of event mentions in Polish text are discussed. A procedure for annotation of event mentions in Polish texts is presented and evaluated. In the evaluation a randomly selected set of documents from the Corpus of Wrocław University of Technology (called KPWr was annotated by two linguists and the annotator agreement was calculated. The evaluation was done in two iterations. After the first evaluation we revised and improved the annotation procedure. The second evaluation showed a significant improvement of the agreement between annotators. The current work was focused on annotation and categorisation of event mentions in text. The future work will be focused on description of event with a set of attributes, arguments and relations.

  17. Named Entity Recognition Using Web Document Corpus

    CERN Document Server

    Karaa, Wahiba Ben Abdessalem

    2011-01-01

    This paper introduces a named entity recognition approach in textual corpus. This Named Entity (NE) can be a named: location, person, organization, date, time, etc., characterized by instances. A NE is found in texts accompanied by contexts: words that are left or right of the NE. The work mainly aims at identifying contexts inducing the NE's nature. As such, The occurrence of the word "President" in a text, means that this word or context may be followed by the name of a president as President "Obama". Likewise, a word preceded by the string "footballer" induces that this is the name of a footballer. NE recognition may be viewed as a classification method, where every word is assigned to a NE class, regarding the context. The aim of this study is then to identify and classify the contexts that are most relevant to recognize a NE, those which are frequently found with the NE. A learning approach using training corpus: web documents, constructed from learning examples is then suggested. Frequency representatio...

  18. The Analysis of The Happy Prince Based on Corpus

    Institute of Scientific and Technical Information of China (English)

    LI Hui

    2014-01-01

    As a new and rising discipline, Corpus Linguistics can be applied in the field of literary criticism to analyze literary text. Analyzing“The Happy Prince”written by the famous British writer Oscar Wilde with corpus can help reveal how the plot, por-traits of people and the rhetorical devices express the theme of the story.

  19. Corpus-based Study on English Synonym Discrimination

    Institute of Scientific and Technical Information of China (English)

    贺倩静

    2014-01-01

    Corpus is widely used with the rapid development of corpus technology.This paper mainly introduces cor-pus-based study on English synonym discrimination which is effective in grasping English near synonyms. This cor-pus-based study may also give some implications on English learning.

  20. Use of "Google Scholar" in Corpus-Driven EAP Research

    Science.gov (United States)

    Brezina, Vaclav

    2012-01-01

    This primarily methodological article makes a proposition for linguistic exploration of textual resources available through the "Google Scholar" search engine. These resources ("Google Scholar virtual corpus") are significantly larger than any existing corpus of academic writing. "Google Scholar", however, was not designed for linguistic searches…

  1. Linguistics, Sociolinguistics, and Corpus Linguistics: Ideal Language Versus Real Language.

    Science.gov (United States)

    De Beaugrande, Robert

    1999-01-01

    Highlights modes of evidence in large corpus research that may be significant for Sociolinguistics. Suggests that corpus data can help Sociolinguistics engage with issues and variations in usage that are less abstract then phonetics, phonology, and grammar but more proximate to the socially vital issues of the 20th century. (Author/VWL)

  2. Designing a Corpus for Translation and Language Teaching.

    Science.gov (United States)

    Bernardini, Silvia

    2003-01-01

    Describes a million-word corpus for English-Italian translation students. Outlines the design, which makes multiple types of comparisons possible among originals and translations and illustrates how to use the corpus to teach sociocultural insights, discourse-structuring expressions, and lexical patterns. (Author/VWL)

  3. DutchParl: A corpus of parliamentary documents in Dutch

    NARCIS (Netherlands)

    Marx, M.; Schuth, A.; Calzolari, N.; Choukri, K.; Maegaard, B.; Mariani, J.; Odijk, J.; Piperidis, S.; Rosner, M.; Tapias, D.

    2010-01-01

    A corpus called DutchParl is created which aims to contain all digitally available parliamentary documents written in the Dutch language. The first version of DutchParl contains documents from the parliaments of The Netherlands, Flanders and Belgium. The corpus is divided along three dimensions: per

  4. TwNC: a Multifaceted Dutch News Corpus

    NARCIS (Netherlands)

    Ordelman, Roeland; Jong, de Franciska; Hessen, van Arjan; Hondorp, Hendri

    2007-01-01

    This contribution describes the Twente News Corpus (TwNC), a multifaceted corpus for Dutch that is being deployed in a number of NLP research projects among which tracks within the Dutch national research programme MultimediaN, the NWO programme CATCH, and the Dutch-Flemish programme STEVIN. The de

  5. Developing Corpus-Based Materials to Teach Pragmatic Routines

    Science.gov (United States)

    Bardovi-Harlig, Kathleen; Mossman, Sabrina; Vellenga, Heidi E.

    2015-01-01

    This article describes how to develop teaching materials for pragmatics based on authentic language by using a spoken corpus. The authors show how to use the corpus in conjunction with textbooks to identify pragmatic routines for speech acts and how to extract appropriate language samples and adapt them for classroom use. They demonstrate how to…

  6. Corpus-Supported Academic Writing: How Can Technology Help?

    Science.gov (United States)

    Chitez, Madalina; Rapp, Christian; Kruse, Otto

    2015-01-01

    Phraseology has long been used in L2 teaching of academic writing, and corpus linguistics has played a major role in the compilation and assessment of academic phrases. However, there are only a few interactive academic writing tools in which corpus methodology is implemented in a real-time design to support formulation processes. In this paper,…

  7. Cadec: A corpus of adverse drug event annotations.

    Science.gov (United States)

    Karimi, Sarvnaz; Metke-Jimenez, Alejandro; Kemp, Madonna; Wang, Chen

    2015-06-01

    CSIRO Adverse Drug Event Corpus (Cadec) is a new rich annotated corpus of medical forum posts on patient-reported Adverse Drug Events (ADEs). The corpus is sourced from posts on social media, and contains text that is largely written in colloquial language and often deviates from formal English grammar and punctuation rules. Annotations contain mentions of concepts such as drugs, adverse effects, symptoms, and diseases linked to their corresponding concepts in controlled vocabularies, i.e., SNOMED Clinical Terms and MedDRA. The quality of the annotations is ensured by annotation guidelines, multi-stage annotations, measuring inter-annotator agreement, and final review of the annotations by a clinical terminologist. This corpus is useful for studies in the area of information extraction, or more generally text mining, from social media to detect possible adverse drug reactions from direct patient reports. The corpus is publicly available at https://data.csiro.au.(1).

  8. Building a semantically annotated corpus of clinical texts.

    Science.gov (United States)

    Roberts, Angus; Gaizauskas, Robert; Hepple, Mark; Demetriou, George; Guo, Yikun; Roberts, Ian; Setzer, Andrea

    2009-10-01

    In this paper, we describe the construction of a semantically annotated corpus of clinical texts for use in the development and evaluation of systems for automatically extracting clinically significant information from the textual component of patient records. The paper details the sampling of textual material from a collection of 20,000 cancer patient records, the development of a semantic annotation scheme, the annotation methodology, the distribution of annotations in the final corpus, and the use of the corpus for development of an adaptive information extraction system. The resulting corpus is the most richly semantically annotated resource for clinical text processing built to date, whose value has been demonstrated through its use in developing an effective information extraction system. The detailed presentation of our corpus construction and annotation methodology will be of value to others seeking to build high-quality semantically annotated corpora in biomedical domains.

  9. Insights from a Learner Corpus as Opposed to a Native Corpus about Cohesive Devices in an Academic Writing Context

    Science.gov (United States)

    Ersanli, Ceylan Yangin

    2015-01-01

    This study reports on the insights from an EFL learner corpora (a total of 151 essays and 49,690 words) generated from essays collected over the years in a Turkish state university from freshmen students enrolling in the Advanced Writing course. The comparison of cohesive devices in the non-native corpus (NNC) with those in a native corpus (NC)…

  10. Consultation de corpus et styles d’apprentissage Corpus consultation and learning styles

    OpenAIRE

    Alex Boulton

    2012-01-01

    Les corpus représentent une ressource avec de multiples possibilités pour l’apprentissage des langues, mais les résultats d’expériences avec les étudiants sont moins convaincants qu’on pourrait l’espérer. Une explication serait que les résultats quantitatifs cachent la diversité des profils d’apprenants. Cette étude décrit une expérience où des étudiants en architecture consultent soit un corpus, soit un dictionnaire pour résoudre des difficultés précises d’usage en anglais, et complètent un ...

  11. Anterior crucate ligament (ACL) injury

    Science.gov (United States)

    ... An anterior cruciate ligament injury is the over-stretching or tearing of the anterior cruciate ligament (ACL) ... may be injured. This is a medical emergency. Prevention Use proper techniques when playing sports or exercising. ...

  12. Metaphor and Corpus Linguistics Metáfora e linguística de corpus

    Directory of Open Access Journals (Sweden)

    Tony Berber Sardinha

    2011-01-01

    Full Text Available In this paper, I look at four different aspects of metaphor research from a corpus linguistic perspective, namely: (1 the lexicogrammar of metaphors, which refers to the patterning of linguistic metaphor revealed by corpus analysis; (2 metaphor probabilities, which is a facet of metaphor that emerges from frequency-based studies of metaphor; (3 dimensions of metaphor variation, or the search for systematic parameters of variation in metaphor use across different registers; and (4 automated metaphor retrieval, which relates to the development of software to help identify metaphors in corpora. I argue that these four aspects are interrelated, and that advances in one of them can drive changes in the others.Neste artigo discuto quarto aspectos da pesquisa sobre metáfora do ponto de vista da linguística de corpus: (1 a lexicogramática das metáforas, que se refere aos padrões da metáfora linguística revelados pela análise de corpus; (2 probabilidades metafóricas, que é uma faceta da metáfora que emerge a partir dos estudos relacionados à freqüência de metáforas; (3 dimensões da variação de metáforas, ou a busca por parâmetros sistemáticos de variação de uso de metáfora em diferentes gêneros; e (4 captura automática de metáfora, que está relacionada ao desenvolvimento de softwares que auxiliam na identificação de metáforas em corpora. I defendo que esses quatro aspectos são interrelacionados, e que progressos em um deles podem acarretar mudanças nos outros.

  13. From Business Corpus to Business Lexicon*

    Directory of Open Access Journals (Sweden)

    Li Lan

    2011-10-01

    Full Text Available

    Abstract: Language corpora are now indispensable to dictionary compilation. They help broaden the role of the dictionary from standardizing the vocabulary to recording a language. The trilingual corpus generated by the Hong Kong Polytechnic University gives a record of business languages used in Hong Kong. It differs from other corpora in that (1 it includes English, Chinese and Japanese; (2 it shows local characteristics; and (3 it focuses on a specific area (financial services, including banking, accounting, auditing, insurance and investment. The paper discusses various issues of setting up a tricorpus, and how to make full use of the data to generate a trilingual lexicon.

    Keywords: MULTILINGUAL, SPECIAL PURPOSE, CORPUS, LEXICON

    Opsomming: Van sakekorpus tot sakeleksikon. Taalkorpora is tans onontbeerlik virdie samestelling van woordeboeke. Hulle help om die rol van die woordeboek uit te brei vanaf diestandaardisering van die woordeskat tot die optekening van ‘n taal. Die drietalige korpus wat deurdie Hongkongse Politegniese Universiteit ontwikkel is, verskaf ‘n opgawe van die saketale wat inHongkong gebruik word. Dit verskil van ander korpora deurdat (1 dit Engels, Chinees and Japaneesinsluit; (2 dit plaaslike eienskappe vertoon; en (3 dit op 'n spesifieke gebied (finansiële dienste,insluitende bankwese, rekeningkunde, ouditering, versekering en belegging fokus. Die artikelbespreek verskillende aspekte van die totstandbrenging van 'n drietalige korpus, en hoe om vollegebruik te maak van die data om 'n drietalige leksikon te genereer.

    Sleutelwoorde: MEERTALIG, SPESIALE DOEL, KORPUS, LEKSIKON

  14. Corpus-Based Word Sense Disambiguation

    Science.gov (United States)

    Fujii, Atsushi

    1998-04-01

    Resolution of lexical ambiguity, commonly termed ``word sense disambiguation'', is expected to improve the analytical accuracy for tasks which are sensitive to lexical semantics. Such tasks include machine translation, information retrieval, parsing, natural language understanding and lexicography. Reflecting the growth in utilization of machine readable texts, word sense disambiguation techniques have been explored variously in the context of corpus-based approaches. Within one corpus-based framework, that is the similarity-based method, systems use a database, in which example sentences are manually annotated with correct word senses. Given an input, systems search the database for the most similar example to the input. The lexical ambiguity of a word contained in the input is resolved by selecting the sense annotation of the retrieved example. In this research, we apply this method of resolution of verbal polysemy, in which the similarity between two examples is computed as the weighted average of the similarity between complements governed by a target polysemous verb. We explore similarity-based verb sense disambiguation focusing on the following three methods. First, we propose a weighting schema for each verb complement in the similarity computation. Second, in similarity-based techniques, the overhead for manual supervision and searching the large-sized database can be prohibitive. To resolve this problem, we propose a method to select a small number of effective examples, for system usage. Finally, the efficiency of our system is highly dependent on the similarity computation used. To maximize efficiency, we propose a method which integrates the advantages of previous methods for similarity computation.

  15. Facetas em dentes anteriores

    OpenAIRE

    Veloso, Helena Rafaela Lourenço Martins

    2015-01-01

    Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária A presente revisão bibliográfica aborda as facetas estéticas em dentes anteriores, pela crescente valorização de um sorriso esteticamente agradável, facto que faz com que as pessoas procurem cada vez mais alternativas de tratamento para melhorar a aparência do seu sorriso. Os dentes anteriores são decisivos na aparência estética e, c...

  16. Corpus Linguistics and the Design of a Response Message

    Science.gov (United States)

    Atwell, E.

    2002-01-01

    Most research related to SETI, the Search for Extra-Terrestrial Intelligence, is focussed on techniques for detection of possible incoming signals from extra-terrestrial intelligent sources (e.g. Turnbull et al. 1999), and algorithms for analysis of these signals to identify intelligent language-like characteristics (e.g. Elliott and Atwell 1999, 2000). However, another issue for research and debate is the nature of our response, should a signal arrive and be detected. The design of potentially the most significant communicative act in history should not be decided solely by astrophysicists; the Corpus Linguistics research community has a contribution to make to what is essentially a Corpus design and implementation project. (Vakoch 1998) advocated that the message constructed to transmit to extraterrestrials should include a broad, representative collection of perspectives rather than a single viewpoint or genre; this should strike a chord with Corpus Linguists for whom a central principle is that a corpus must be "balanced" to be representative (Meyer 2001). One idea favoured by SETI researchers is to transmit an encyclopaedia summarising human knowledge, such as the Encyclopaedia Britannica, to give ET communicators an overview and "training set" key to analysis of subsequent messages. Furthermore, this should be sent in several versions in parallel: the text; page-images, to include illustrations left out of the text-file and perhaps some sort of abstract linguistic representation of the text, using a functional or logic language (Ollongren 1999, Freudenthal 1960). The idea of "enriching" the message corpus with annotations at several levels should also strike a chord with Corpus Linguists who have long known that Natural language exhibits highly complex multi-layering sequencing, structural and functional patterns, as difficult to model as sequences and structures found in more traditional physical and biological sciences. Some corpora have been annotated with

  17. Intradural anterior transpetrosal approach.

    Science.gov (United States)

    Ichimura, Shinya; Hori, Satoshi; Hecht, Nils; Czabanka, Marcus; Vajkoczy, Peter

    2016-10-01

    The standard anterior transpetrosal approach (ATPA) for petroclival lesions is fundamentally an epidural approach and has been practiced for many decades quite successfully. However, this approach has some disadvantages, such as epidural venous bleeding around foramen ovale. We describe here our experience with a modified technique for anterior petrosectomy via an intradural approach that overcomes these disadvantages. Five patients with petroclival lesions underwent surgery via the intradural ATPA. The intraoperative hallmarks are detailed, and surgical results are reported. Total removal of the lesions was achieved in two patients with petroclival meningioma and two patients with pontine cavernoma, whereas subtotal removal was achieved in one patient with petroclival meningioma without significant morbidity. No patient experienced cerebrospinal fluid leakage. The intradural approach is allowed to tailor the extent of anterior petrosectomy to the individually required exposure, and the surgical procedure appeared to be more straightforward than via the epidural route. Caveats encountered with the approach were the temporal basal veins that could be spared as well as identification of the petrous apex due to the lack of familial epidural landmarks. The risk of injury to the temporal bridging veins is higher in this approach than in the epidural approach. Intradural approach is recommended in patients with a large epidural venous route, such as sphenobasal and sphenopetrosal vein. Navigation via bone-window computed tomography is useful to identify the petrous apex.

  18. Application of multilingual corpus in contrastive studies (on the example of the Bulgarian-Polish-Lithuanian parallel corpus

    Directory of Open Access Journals (Sweden)

    Ludmila Dimitrova

    2015-11-01

    Full Text Available Application of multilingual corpus in contrastive studies (on the example of the Bulgarian-Polish-Lithuanian parallel corpus In this paper we present applications of a trilingual corpus in language research. Comparative and contrastive studies of Polish and Bulgarian as well as Polish and Lithuanian have been already conducted, but up to the best of our knowledge no such studies exist for Bulgarian and Lithuanian. On the one hand, it is interesting to note that two Slavic languages are compared to a Baltic language (Lithuanian. On the other hand, the three languages are marginally present in the EU because of the later ascension of the three countries to the EU. The paper shortly describes the first electronic Bulgarian–Polish–Lithuanian experimental corpus, currently under development only for research. We also focus our attention on the morphosyntactic annotation of the parallel trilingual corpus according to the Corpus Encoding Standard: we present a review of the Part-of-Speech (POS classification of the participle in the three languages – Bulgarian, Polish, and Lithuanian in comparison to another POS, the adjective. We briefly discuss tagsets for corpus annotation from the point of view of possible unification in the future with some examples.

  19. FTA Corpus: a parallel corpus of English and Spanish Free Trade Agreements for the study of specialized collocations

    Directory of Open Access Journals (Sweden)

    Pedro Patiño García

    2013-04-01

    Full Text Available This paper describes the Corpus of Free Trade Agreements (henceforth FTA, a specialized parallel corpus in English and Spanish from Europe and America and a smaller subcorpus in English-Norwegian and Spanish-Norwegian that was prepared and then aligned with Translation Corpus Aligner 2 (Hofland & Johansson, 1998. The data was taken from Free Trade Agreements. These agreements are specialized texts officially signed and ratified by several countries and blocks of countries in the last twenty years. Thus, FTAs are a rich repository for terminology and phraseology that is used in different fields of business activity throughout the world. The corpus contains around 1.37 million words in the English section and 1.48 million words in its Spanish counterpart, plus 60,000 words each in the Spanish-Norwegian and English-Norwegian subcorpus. The corpus is being used primarily to study the terms and specialized collocations that include these terms in this kind of specialized texts.Keywords: specialized collocation, specialized parallel corpus, corpus linguistics, Free Trade Agreement

  20. New Advances in Corpus-based Lexicography*

    Directory of Open Access Journals (Sweden)

    Arvi Hurskainen

    2011-10-01

    Full Text Available

    Abstract: This article presents various approaches used in corpus-based computational lexico-graphy. A claim is made that in order for computational lexicography to be efficient, precise and comprehensive, it should utilize the method where the corpus text is first analysed, and the results of this analysis is then processed further to meet the needs of a dictionary. This method has several advantages, including high precision and recall, as well as the possibility to automate the process much further than with more traditional computational methods. The frequency list obtained by using the lemma (the equivalent of the headword as basis helps in selecting the words to be in-cluded in the dictionary. The approach is demonstrated through various phases by applying SALAMA (the Swahili Language Manager to the process. Manual work will be needed in the phase when examples of use are selected from the corpus, and possibly modified. However, the list of examples of use, arranged alphabetically according to the corresponding headword, can also be produced automatically. Thus the alphabetical list of headwords with examples of use is the mate-rial on which the lexicographer works manually. The article deals with problems encountered in compiling traditional printed dictionaries, and it excludes electronic dictionaries and thesauri.

    Keywords: LEXICOGRAPHY, DICTIONARY, LANGUAGE TECHNOLOGY, COMPUTA-TIONAL LINGUISTICS, AUTOMATIC COMPILATION, DICTIONARY TESTING, INFORMA-TION RETRIEVAL, MORPHOLOGICAL ANALYSIS, SEMANTIC ANALYSIS, DISAMBIGUA-TION, HEURISTICS

    Opsomming: Nuwe ontwikkelinge in korpusgebaseerde leksikografie. Hier-die artikel beskryf verskillende benaderings wat in korpusgebaseerde rekenaarleksikografie ge-bruik word. Daar word aangevoer dat vir rekenaarleksikografie om doelmatig, noukeurig en omvattend te wees, dit die metode behoort te gebruik waarby die korpusteks eers ontleed word, en die resultaat van hierdie ontleding dan verder

  1. A Corpus-based Discourse Analysis on Barack Obama’s Weekly Addresses

    Institute of Scientific and Technical Information of China (English)

    陈凯丽

    2015-01-01

    With the development and application of computational corpus, corpus linguistics has made great development. The daily life has seen the application and significance of corpus. Especialy in teaching for it can not only supply textbooks directly but also plays a large role in the outline of textbook and composition correction. Hence, corpus is widely applied.

  2. Anterior knee pain

    Energy Technology Data Exchange (ETDEWEB)

    LLopis, Eva [Hospital de la Ribera, Alzira, Valencia (Spain) and Carretera de Corbera km 1, 46600 Alzira Valencia (Spain)]. E-mail: ellopis@hospital-ribera.com; Padron, Mario [Clinica Cemtro, Ventisquero de la Condesa no. 42, 28035 Madrid (Spain)]. E-mail: mario.padron@clinicacemtro.com

    2007-04-15

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries.

  3. Architecture of the Corpus Spongiosum : An Anatomical Study

    NARCIS (Netherlands)

    Ottenhof, Sarah R; de Graaf, Petra; Soeterik, Timo F W; Neeter, Lidewij M F H; Zilverschoon, Marijn; Spinder, Matty; Bosch, J L H Ruud; Bleys, Ronald L A W; Heck-de Kort, Laetitia

    2016-01-01

    PURPOSE: Urethral reconstruction is performed for urethral stricture or hypospadias correction. Research on urethral tissue engineering is increasing. Because the corpus spongiosum is important to support the urethra, urethral tissue engineering should ideally be combined with reconstruction of a co

  4. OLD RUSSIAN MANUSCRIPTS IN THE RUSSIAN NATIONAL CORPUS

    Directory of Open Access Journals (Sweden)

    A. M. Moldovan

    2015-01-01

    Full Text Available The article deals with different types of the corpus representation of Old Russian manuscripts in their ability to solve linguistics problems. Collections of digital copies and e-books in PDF and DjVu formats are the simplest and widely spread type of electronic resources, containing old Russian manuscripts. Theoretically  more interesting, though much more difficult, is the representation  of digitized  editions as textual corpora and databases.  The main attention in the article is paid to the historical subcorpus within the Russian National Corpus representing the sources of the XI-XVII centuries and consisting of four parts: the Old Russian corpus, the Corpus of birchbark letters, the Middle Russian and the Church-Slavonic corpora.

  5. Linguistic complexity: English vs. Polish, text vs. corpus

    CERN Document Server

    Kwapien, Jaroslaw; Orczyk, Adam

    2010-01-01

    We analyze the rank-frequency distributions of words in selected English and Polish texts. We show that for the lemmatized (basic) word forms the scale-invariant regime breaks after about two decades, while it might be consistent for the whole range of ranks for the inflected word forms. We also find that for a corpus consisting of texts written by different authors the basic scale-invariant regime is broken more strongly than in the case of comparable corpus consisting of texts written by the same author. Similarly, for a corpus consisting of texts translated into Polish from other languages the scale-invariant regime is broken more strongly than for a comparable corpus of native Polish texts. Moreover, we find that if the words are tagged with their proper part of speech, only verbs show rank-frequency distribution that is almost scale-invariant.

  6. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  7. On the application of corpus in Chinese-English translations

    Institute of Scientific and Technical Information of China (English)

    陈梦蕾

    2013-01-01

    In translating from Chinese to English, we Chinese tend to rely on dictionaries or sometimes simply intuition to choose lexes. However, the translated texts still read not that idiomatic as the native speakers',the basic reason lying in the inappropriate collocations. For-tunately, the discovery of corpus laid the quantized basis for the study of collocational behaviors. This article aims to discuss the functions of corpus in bettering C- E translations.

  8. Experimental Polish-Lithuanian Corpus with the Semantic Annotation Elements

    Directory of Open Access Journals (Sweden)

    Danuta Roszko

    2015-06-01

    Full Text Available Experimental Polish-Lithuanian Corpus with the Semantic Annotation Elements In the article the authors present the experimental Polish-Lithuanian corpus (ECorpPL-LT formed for the idea of Polish-Lithuanian theoretical contrastive studies, a Polish-Lithuanian electronic dictionary, and as help for a sworn translator. The semantic annotation being brought into ECorpPL-LT is extremely useful in Polish-Lithuanian contrastive studies, and also proves helpful in translation work.

  9. The Corpus of English as Lingua Franca in Academic Settings.

    Science.gov (United States)

    Mauranen, Anna

    2003-01-01

    Describes a project to make a corpus of English spoken as a lingua franca in university settings in Finland. This corpus is one of the first to address the need for corpora that show the target for English-as-a-Foreign-Language learners whose goal is not to speak with native speakers but to interact in communities where English is a lingua franca.…

  10. Acute aortic dissection type A discloses Corpus alienum

    Directory of Open Access Journals (Sweden)

    Kolat Philipp

    2009-01-01

    Full Text Available Abstract We report an unusual case of an aortic type A dissection with a corpus alienum which compresses the right ventricle. The patient successfully underwent an aortic root replacement in deep hypothermia with re-implantation of the coronary arteries using a modified Bentall procedure and the resection of the corpus alienum. Intraoperative finding reveals 3 greatly adhered gauze compresses, which were most likely forgotten in the operation 34 years ago.

  11. Acute aortic dissection type A discloses Corpus alienum

    Science.gov (United States)

    Popov, Aron Frederik; Baryalei, Mersa Mohammed; Schmitto, Jan Dieter; Hinz, Jose; Wiese, Christoph Hermann; Raab, Björn; Kolat, Philipp; Schoendube, Friedrich Albert; Seipelt, Ralf

    2009-01-01

    We report an unusual case of an aortic type A dissection with a corpus alienum which compresses the right ventricle. The patient successfully underwent an aortic root replacement in deep hypothermia with re-implantation of the coronary arteries using a modified Bentall procedure and the resection of the corpus alienum. Intraoperative finding reveals 3 greatly adhered gauze compresses, which were most likely forgotten in the operation 34 years ago. PMID:19121214

  12. Multi-annotation discursive de corpus écrit

    OpenAIRE

    Péry-Woodley, Marie-Paule

    2011-01-01

    National audience; On the basis of the experience acquired in the course of the ANNODIS project, the following questions are discussed: - what is the annotation campaign for? building an annotated " reference corpus" vs. annotation as an experiment; - defining annotation tasks. Naïve vs. expert annotation; - the annotation manual : from linguistic model to annotation protocol; - automatic pre-processing vs. manual annotation. Segmentation, tagging and mark-ups: steps in corpus preparation; - ...

  13. Detecting Code-Switching in a Multilingual Alpine Heritage Corpus

    OpenAIRE

    Volk, Martin; Clematide, Simon

    2014-01-01

    This paper describes experiments in detecting and annotating code-switching in a large multilingual diachronic corpus of Swiss Alpine texts. The texts are in English, French, German, Italian, Romansh and Swiss German. Because of the multilingual authors (mountaineers, scientists) and the assumed multilingual readers, the texts contain numerous code-switching elements. When building and annotating the corpus, we faced issues of language identification on the sentence and sub-sentential level. ...

  14. Building a Large Annotated Corpus of English: The Penn Treebank

    Science.gov (United States)

    1993-04-30

    Brill 1991]) or the skeletally parsed corpus ([Weischedel et al 1991], [Pereira and Schabes 1992]). The POS-tagged corpus has also been used to train a...Niv 1991] Niv, Michael, 1991. Syntactic disambiguation. In The Penn Review of Linguistics 14, pages 120-126. [Pereira and Schabes 1992] Pereira...Fernando and Schabes , Yves. 1992. Inside-outside reestimation from partially bracketed corpora. In Proceedings of the 30th Annual Meeting of the

  15. lexiDB:a scalable corpus database management system

    OpenAIRE

    Coole, Matt; Rayson, Paul Edward; Mariani, John Amedeo

    2016-01-01

    lexiDB is a scalable corpus database management system designed to fulfill corpus linguistics retrieval queries on multi-billion-word multiply-annotated corpora. It is based on a distributed architecture that allows the system to scale out to support ever larger text collections. This paper presents an overview of the architecture behind lexiDB as well as a demonstration of its functionality. We present lexiDB's performance metrics based on the AWS (Amazon Web Services) infrastructure with tw...

  16. Paediatric Virology in the Hippocratic Corpus

    Science.gov (United States)

    Mammas, Ioannis N.; Spandidos, Demetrios A.

    2016-01-01

    Hippocrates (Island of Kos, 460 B.C.-Larissa, 370 B.C.) is the founder of the most famous Medical School of the classical antiquity. In acknowledgement of his pioneering contribution to the new scientific field of Paediatric Virology, this article provides a systematic analysis of the Hippocratic Corpus, with particular focus on viral infections predominating in neonates and children. A mumps epidemic, affecting the island of Thasos in the 5th century B.C., is described in detail. ‘Herpes’, a medical term derived from the ancient Greek word ‘ἕρπειν’, meaning ‘to creep’ or ‘crawl’, is used to describe the spreading of cutaneous lesions in both childhood and adulthood. Cases of children with exanthema ‘resembling mosquito bites’ are presented in reference to varicella or smallpox infection. A variety of upper and lower respiratory tract viral infections are described with impressive accuracy, including rhinitis, pharyngitis, tonsillitis, laryngitis, bronchiolitis and bronchitis. The ‘cough of Perinthos’ epidemic, an influenza-like outbreak in the 5th century B.C., is also recorded and several cases complicated with pneumonia or fatal outcomes are discussed. Hippocrates, moreover, describes conjunctivitis, otitis, lymphadenitis, meningoencephalitis, febrile convulsions, gastroenteritis, hepatitis, poliomyelitis and skin warts, along with proposed treatment directions. Almost 2,400 years later, Hippocrates' systematic approach and methodical innovations can inspire paediatric trainees and future Paediatric Virology subspecialists. PMID:27446241

  17. Chinese EFL Teachers' Attitudes toward Corpus Use in Collocation Instruction

    Institute of Scientific and Technical Information of China (English)

    郭敏

    2014-01-01

    The purpose of the present study was to investigate Chinese EFL (English as a Foreign Language) teachers ’attitudes to-ward corpus use in collocation instruction. Fourteen Chinese EFL teachers from seven different colleges or universities answered a questionnaire asking their perceptions about corpus use in collocation instruction. The statistical analysis revealed that significant difference (t=2.449, df.=9, p=.037<0.1) was found between males and females in their perception of the learnability of the search-ing technique in collocation corpus. Besides, the result also revealed that significant differences were found between novice and experienced teachers’perception of helpfulness of corpus in writing native-like sentences (t=5.75, df=11, p<0.1), identifying col-location errors in English (t=5.75, df=11, p<0.1), usefulness of corpus in searching for English collocations (t=2.93, df=12, p<0.1), and advocacy of corpus to colleagues(t=5.75, df=11, p<0.1). Finally, some pedagogical implications were put forward.

  18. The Chinese-English Translational Corpus of Ecotourism in Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tong

    2016-01-01

    Having reviewed the history of the development of the corpus, especially the translation corpus, this paper explicated the importance of building a Chinese-English translational corpus for specific areas on the basis of the status quo of corpus and the translation need in China. Then how to build a translational corpus of ecotourism promotional materials centred on Inner Mongolia, as well as its applications, is thoroughly discussed.

  19. The Application of Corpus-based Lexical Chunks Approach in English Teaching

    Institute of Scientific and Technical Information of China (English)

    梅王星

    2015-01-01

    With the guidance of lexical chunks teaching approach, this article is to discuss the application of corpus-based lexical chunks approach in English teaching by making use of corpus concordance analysis.After comparing the language differences between native language corpus and target language corpus, it advocates that the emphasis of English lexical study should be put on corpus-based study of chunks, aiming to promote the fluency and authenticity of language output in English teaching.

  20. Multidisciplinary management of anterior diastemata

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; Herkrath, Fernando José; Franco, Eduardo Jacomino

    2007-01-01

    Anterior diastemata may compromise the harmony of a patient's smile. Consideration of etiologic factors, previous gingival conditioning, and individual treatment planning are essential in the proper management of anterior diastemata. An integrated orthodontic-restorative approach may enhance...... the aesthetic results when orthodontic therapy itself is not feasible. This article presents integrated orthodonticrestorative solutions of anterior diastemata, associated with the conditioning of the gingival tissue with composite resin, and discusses the most relevant aspects related to their etiology...

  1. Contrast radiographic study of venous drainage of the corpus cavernosum and the corpus spongiosum of the cat penis.

    Science.gov (United States)

    Amiri, Ali Akbar; Gilanpour, Hassan; Veshkini, Abbas

    2014-01-01

    The aim of this study was to determine the drainage routes of the corpus cvernosum penis and the corpus spongiosum penis in the cat using contrast cavernosography. Five male cats, 1.5-2.5 years old, weighing between 4.5 and 5.5 kg were investigated. The cats were anesthetized and the root and the proximal part of the penis were exposed by an incision on the perineum reaching the scrotum. Each cat was radiographed in lateral and dorsal recumbency before and during injection of contrast medium into the erectile bodies. The corpus spongiosum penis was injected at the bulb of the penis and the corpus cavernosum penis at the root. Injection of contrast media into the cavernous bodies showed that both the external and internal iliac veins drain the erectile bodies into the caudal vena cava. Drainage from the corpus spongiosum penis was from the bulb for the proximal part and from the glans for the distal part. The corpus cavernosum penis was drained only proximally, from the crura. There was a network of veins above the pelvic symphysis and the drainage of erectile bodies where through various routes into the internal and external iliac veins.

  2. Posterior alien hand syndrome: case report

    Energy Technology Data Exchange (ETDEWEB)

    Rohde, S.; Weidauer, S.; Lanfermann, H.; Zanella, F. [Institute of Neuroradiology, Johann Wolfgang Goethe University, Schleusenweg 2-16, 60528 Frankfurt am Main (Germany)

    2002-11-01

    The alien hand syndrome (AHS) is involuntary uncontrolled movement of an arm with a sense of estrangement from the limb itself. AHS was initially used to describe interhemispheric disconnection phenomena in patients with lesions in the anterior corpus callosum, but it has been found in patients with posterior cerebral lesions without involvement of the corpus callosum, for example parietal infarcts or corticobasal degeneration. The posterior alien hand syndrome is less frequent and presents with nonpurposive behaviour like lifting the arm or writhing fingers. We report an 80-year-old woman with a posterior AHS of the dominant right hand. MRI showed atrophy of the pre- and postcentral gyri without involvement of the corpus callosum. We discuss the aetiology of the posterior AHS and the differences from the anterior varieties. (orig.)

  3. [Anterior cervical hypertrichosis: case report].

    Science.gov (United States)

    Orozco-Gutiérrez, Mario H; Sánchez-Corona, José; García-Ortiz, José E; Castañeda-Cisneros, Gema; Dávalos-Rodríguez, Nory O; Corona-Rivera, Jorge R; García-Cruz, Diana

    2016-10-01

    The non-syndromic anterior cervical hypertrichosis (OMIM N° 600457) is a genetic disorder characterized by a patch of hair at the level of the laryngeal prominence. We present a 12-year-old boy with anterior cervical hypertrichosis and mild generalized hypertrichosis. He has no neurological, ophthalmological or skeletal anomalies. The clinical follow up is 10 years.

  4. Exploring theoretical functions of corpus data in teaching translation

    Directory of Open Access Journals (Sweden)

    Éric Poirier

    2016-06-01

    Full Text Available As language referential data banks, corpora are instrumental in the exploration of translation solutions in bilingual parallel texts or conventional usages of source or target language in monolingual general or specialized texts. These roles are firmly rooted in translation processes, from analysis and interpretation of source text to searching for an acceptable equivalent and integrating it into the production of the target text. Provided the creative and not the conservative way be taken, validation or adaptation of target text in accordance with conventional usages in the target language also benefits from corpora. Translation teaching is not exploiting this way of translating that is common practice in the professional translation markets around the world. Instead of showing what corpus tools can do to translation teaching, we start our analysis with a common issue within translation teaching and show how corpus data can help to resolve it in learning activities in translation courses. We suggest a corpus-driven model for the interpretation of ‘business’ as a term and as an item in complex terms based on source text pattern analysis. This methodology will make it possible for teachers to explain and justify interpretation rules that have been defined theoretically from corpus data. It will also help teachers to conceive and non-subjectively assess practical activities designed for learners of translation. Corpus data selected for the examples of rule-based interpretations provided in this paper have been compiled in a corpus-driven study (Poirier, 2015 on the translation of the noun ‘business’ in the field of specialized translation in business, economics, and finance from English to French. The corpus methodology and rule-based interpretation of senses can be generalized and applied in the definition of interpretation rules for other language pairs and other specialized simple and complex terms. These works will encourage the

  5. Corpus Linguistics: Influencing and contributing to the EFL classroom

    OpenAIRE

    Fritz, Robinson

    2010-01-01

    本論文は英語教育の中でCorpus Linguisticsが、どのように教育学に貢献し、また影響を及ぼしているのかについて考察した。初めに、Corpus Linguisticsについての大まかな理論と、Corpus Linguisticsが新しい一つの手段として今までの規則を変化させる方法について述べている。次に、英語の教育や学習にCorpus Linguisticsが様々な方法で利益をもたらしてるいこと、また教育者にとって役立つことについて述べている。最後に、Corpus Linguisticsを用いて、語彙学習時にどのようにしてEFL学生を援助できるかについて述べている。...

  6. Inestabilidad Anterior de Hombro

    Directory of Open Access Journals (Sweden)

    Pablo David Flint Kuran

    2013-11-01

    Full Text Available In­tro­duc­ción La luxación recidivante de hombro es una patología frecuente en pacientes jóvenes, laboralmente activos. Existen numerosas técnicas quirúrgicas para la inestabilidad glenohumeral. La técnica de Bristow, discutida por no ser anatómica y por sus complicaciones, continúa vigente debido al bajo índice de reluxaciones. Los objetivos fueron determinar el índice de recidiva, alteraciones funcionales e índice de consolidación del injerto. Materiales­ y­ Métodos Se evaluaron 24 pacientes del sexo masculino, de entre 19 y 40 años, operados por luxación anterior recidivante de hombro según la técnica de Bristow, entre enero de 2003 y agosto de 2011. Se evaluó la tasa de reluxación, la función articular según el puntaje de Constant y el posicionamiento del injerto con respecto a la superficie articular con tomografía y radiografías para evaluar la consolidación del injerto. Se registraron las complicaciones quirúrgicas. Resultados ­Todos los pacientes eran hombres, con rango de edad de 19 a 40 años. La causa fue traumática en 24 pacientes. Dieciséis pacientes presentaron más de 3 episodios de luxación prequirúrgicos. Según la escala de Constant, 21 obtuvieron entre 96 y 100 puntos, y los restantes, entre 90 y 95 puntos. No hubo nuevos episodios de luxaciones. La tomografía mostró la consolidación en todos los casos. Un paciente tuvo una imagen osteolítica alrededor del tornillo, sin compromiso funcional del hombro. Conclusión La técnica de Bristow para tratar la luxación anterior recidivante de hombro provocó un bajo índice de complicaciones, con resultados funcionales entre excelentes y buenos. No hubo episodios de reluxación y se logró la consolidación del injerto óseo en todos los casos.

  7. Trilingual aligned corpus – current state and new applications

    Directory of Open Access Journals (Sweden)

    Ludmila Dimitrova

    2014-09-01

    Full Text Available Trilingual aligned corpus – current state and new applications This article describes current state of a trilingual parallel corpus consisted of texts in two Slavic (Bulgarian and Polish and one Baltic language (Lithuanian. The corpus contains original literary texts (fiction, novels, and short stories in one of the three languages with translations to the other two, and texts in other languages translated into Bulgarian, Polish, and Lithuanian. A part of the texts are aligned at the sentence level. The authors propose a semantic annotation of verbs appearing in these aligned texts that will facilitate contrastive studies of natural languages. A theoretical background for the proposed semantic annotation is briefly also discussed.

  8. Icariin on relaxation effect of corpus cavernosum smooth muscle

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    NO-cGMP pathway in penile corpus cavernosal smooth muscle plays an important role in penile erection. The level of cGMP is regulated by a balance between the rate of synthesis by guanylate cyclase and the rate of hydrolytic breakdown to guanosine 5′monophosphate (GMP) by phos- phodiesterase 5(PDE5). Icariin is isolated from natural drug Epimedii herba, it is shown to have the relaxation effect on corpus cavernosal smooth muscle of rabbit (IC50: 4×10-4 mol/L), and the mechanism of the relaxation effect of Icariin on corpus cavernosum believed to have the inhibiting effect on PDE5 and activation of NO-cGMP pathway to enhancing penile erection.

  9. Introduction to an Interlanguage Corpus-WECCL 2.0

    Institute of Scientific and Technical Information of China (English)

    WANG Guan

    2013-01-01

    Authentic and objective material with regard to a certain language is the bare necessity and premise of any kind of lin⁃guistic research and then on the basis of the data, corpus-based approach, which is also addressed as a performance-based ap⁃proach, has been involved in almost every corner of linguistics. Thus far, it is hardly surprising that some typical Corpora are essen⁃tial for contemporary Chinese EFL’s study. WECCL 2.0, as a representative of interlanguage corpus, is introduced in this paper.

  10. A multimodal corpus of speech to infant and adult listeners.

    Science.gov (United States)

    Johnson, Elizabeth K; Lahey, Mybeth; Ernestus, Mirjam; Cutler, Anne

    2013-12-01

    An audio and video corpus of speech addressed to 28 11-month-olds is described. The corpus allows comparisons between adult speech directed toward infants, familiar adults, and unfamiliar adult addressees as well as of caregivers' word teaching strategies across word classes. Summary data show that infant-directed speech differed more from speech to unfamiliar than familiar adults, that word teaching strategies for nominals versus verbs and adjectives differed, that mothers mostly addressed infants with multi-word utterances, and that infants' vocabulary size was unrelated to speech rate, but correlated positively with predominance of continuous caregiver speech (not of isolated words) in the input.

  11. The Shona Corpus and the Problem of Tagging?

    Directory of Open Access Journals (Sweden)

    Emmanuel Chabata

    2011-10-01

    Full Text Available

    Abstract: In this paper the writer examines problems the African Languages Lexical (ALLEX Project (at present the African Languages Research Institute (ALRI? encountered while tagging the Shona corpus. The problems to be highlighted include general problems which apply to more than one language as well as problems peculiar to Shona. The paper was inspired by the challenges the writer encountered when he took part in building the Shona corpus. An analysis of the problems that most corpus builders face shows that more problems are likely to be encountered when dealing with spoken corpora than with written corpora. The paper demonstrates that tagging is an important component of corpus building as it makes it easier for a researcher to extract relevant data. To utilise the benefits of a tagged corpus, the tagging should be thorough and accurate. Wellinformed decisions form an integral part of the tagging process since the utility of a tagged corpus depends largely on the input of the tagging process. This paper shows the need to take the tagging process seriously.

    Keywords: ALLEX PROJECT, COMPUTER, CORPUS, ENCODING, FOREIGN WORD, LEMMATIZATION, LEXICOGRAPHY, MONITOR CORPUS, PART OF SPEECH, SCANNING, SHONA, SLANG, TAGGING, TRANSCRIPTION, WORD

    Opsomming: Die Shonakorpus en die probleem van etikettering, In hierdieartikel ondersoek die outeur probleme wat die African Languages Lexical (ALLEX Project (tansdie African Languages Research Institute (ALRI» teegekom het terwyl die Shonakorpus geetiketteeris. Die probleme wat bespreek word, sluit algemene probleme in wat van toepassing is opmeer as een taa, sowel as spesifieke probleme wat eie aan Shona is. Die artikel het sy ontstaan indie uitdagings wat die outeur teegekom het terwyl hy deel gehad het aan die opbou van die Shonakorpus.'n Ontieding van die probleme waarvoor die meeste korpusbouers te staan kom, toon datdaar waarskynlik meer probleme teegekom word wanneer daar met gesproke

  12. Similarity and Difference in Corpus-based Translation Studies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Corpus-based translation studies has grown considerably over the past fifteen years or so. This paper appraises the uniformity and diversity of descriptive corpus studies of translation in terms of divergent similarity, as intended by Andrew Chesterman (1996, 2004a, 2006). The analysis focuses on the state of the art of research into translation universals, highlighting the interdisciplinary nature of current investigations and their contribution to the progress of the discipline as a whole. The general framework proposed by Chesterman is also used to introduce an envisaged study of Anglicisms whose aim is twofold: to unveil the translation-specific lexical primings of English loan genre.

  13. Combining Corpus and Cognitive Linguistics in English Lexical Teaching

    Institute of Scientific and Technical Information of China (English)

    朱雨佳

    2013-01-01

      Although numerous researches have been done on corpus and cognitive linguistics, only a few researches combine them together, especially in language teaching. It provides a theoretical guidance for combining corpus and cognitive linguistics in Eng⁃lish lexical teaching. Linguists should take both the frequency and cognitive theories into consideration when they decide which word should be included in the lexical syllabus because there is sometimes a difference between the frequency and the tuition. What’s more, the combination in lexical teaching can help EFL (English as a Foreign Language) learners to better deal with some common problems such as homonymy and synonymy.

  14. Corpus Juris ja Eesti : [bakalaureusetöö] / Artur Kink ; Tartu Ülikool, õigusteaduskond ; juhendaja: Eerik Kergandberg

    Index Scriptorium Estoniae

    Kink, Artur

    1999-01-01

    Corpus Jurise taust ja areng - finantshuvide kaitse areng, Corpus Jurise ajalugu; Corpus Jurise õiguslik baas (Amsterdami leping), ülesehitus ja struktuur (üleeuroopalise territoriaalsuse printsiip, kohtuliku kontrolli printsiip, "vastuväitelise" protsessi printsiip, kohaliku õiguse subsidiaarsuse printsiip)

  15. An Investigation into the Role of Corpus Linguistics in Language Teaching

    Institute of Scientific and Technical Information of China (English)

    付期棉

    2014-01-01

    This article explores the features of corpus linguistics and its implication for language teaching. Through literature re-view, this paper points out that corpus linguistics plays an important role in the three major sections in language teaching, namely, materials development, classroom activities and language testing. In addition, the role of learner corpus in language teaching is al-so explored. The challenges facing the application of corpus linguistics into language teaching is finally discussed.

  16. Using a Corpus in an EFL Classroom to Develop Depth of Vocabulary Knowledge

    OpenAIRE

    峰松, 和子; MINEMATSU, Kazuko

    2014-01-01

    A corpus is a collection of written or spoken texts, which is stored on a computer. Thispaper examines whether or not a corpus can be used to develop depth of vocabularyknowledge in an EFL classroom. The advantages of using a corpus lie in its authenticity anduse of abundant examples. This suggest that a corpus could be used in fruitful ways tobroaden or deepen learners’ vocabulary. This paper focuses on the latter: developing depthof vocabulary knowledge. Data-driven learning (DLL) is one me...

  17. Anterior chamber depth during hemodialysis

    Directory of Open Access Journals (Sweden)

    Gracitelli CPB

    2013-08-01

    Full Text Available Carolina Pelegrini Barbosa Gracitelli,1 Francisco Rosa Stefanini,1 Fernando Penha,1 Miguel Ângelo Góes,2 Sérgio Antonio Draibe,2 Maria Eugênia Canziani,2 Augusto Paranhos Junior1 1Ophthalmology Department, 2Division of Nephrology, Federal University of São Paulo – UNIFESP, São Paulo, Brazil Background: Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD because of anterior chamber depth changes during this therapy. Purpose: To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods: A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results: There was no difference in the axial length between the three measurements (P = 0.241. We observed a significantly decreased anterior chamber depth (P = 0.002 during HD sessions. Conclusion: Our results support the idea that there is a change in anterior chamber depth in HD sessions. Keywords: anterior chamber, hemodialysis, axial length, acute angle-closure glaucoma

  18. Diffuse anterior retinoblastoma: current concepts

    Directory of Open Access Journals (Sweden)

    Yang J

    2015-07-01

    Full Text Available Jing Yang,1–3 Yalong Dang,1–3 Yu Zhu,1 Chun Zhang2,3 1Department of Ophthalmology, The First Affiliated Hospital, Zhengzhou University, Zhengzhou City, Henan Province, 2Department of Ophthalmology, Peking University Third Hospital, 3Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, People’s Republic of China Abstract: Diffuse anterior retinoblastoma is a rare variant of retinoblastoma seeding in the area of the vitreous base and anterior chamber. Patients with diffuse anterior retinoblastoma are older than those with the classical types, with the mean age being 6.1 years. The original cells of diffuse anterior retinoblastoma are supposed to be cone precursor. Patients most commonly present with pseudouveitis, pseudohypopyon, and increased intraocular pressure. The retina under fundus examination is likely to be normal, and the clinical features mimic the inflammation progress, which can often lead to misdiagnosis. The published diffuse anterior retinoblastoma cases were diagnosed after fine-needle aspiration biopsy running the potential risk of inducing metastasis. The most common treatment for diffuse anterior retinoblastoma is enucleation followed by systematic chemotherapy according to the patient’s presentation and clinical course. This review summarizes the recent advances in etiology (including tumorigenesis and cell origin, pathology, diagnosis, differential diagnosis, and new treatment. The challenges of early diagnosis and prospects are also discussed. Keywords: pathology, microenvironment, treatment, diagnosis 

  19. A Danish phonetically annotated spontaneous speech corpus (DanPASS)

    DEFF Research Database (Denmark)

    Grønnum, Nina

    2009-01-01

    A corpus is described consisting of non-scripted monologues and dialogues, recorded by 27 speakers, comprising a total of 73,227 running words, corresponding to 9 h and 46 min of speech. The monologues were recorded as one-way communication with an unseen partner where the speaker performed three...

  20. The Use of Corpus Examples for Language Comprehension and Production

    Science.gov (United States)

    Frankenberg-Garcia, Ana

    2014-01-01

    One of the many new features of English language learners' dictionaries derived from the technological developments that have taken place over recent decades is the presence of corpus-based examples to illustrate the use of words in context. However, empirical studies have generally not been able to produce conclusive evidence about their…

  1. Creating an Information Retrieval test corpus for Dutch

    NARCIS (Netherlands)

    Hiemstra, D.; Leeuwen, van D.A.; Theune, M.; Nijholt, A.; Hondorp, G.H.W.

    2002-01-01

    This paper describes the first large-scale evaluation of information retrieval systems using Dutch documents and queries. We describe in detail the characteristics of the Dutch test data, which is part of the official CLEF multilingual test corpus, and give an overview of the experimental results of

  2. Reproducibility of corpus cavernosum electromyography in healthy young man

    NARCIS (Netherlands)

    Jiang, X.; Frantzen, J.; Holsheimer, J.; Meuleman, E.

    2005-01-01

    Research on reproducibility of corpus cavernosum electromyography (CC-EMG) is relevant because reproducible signals indicate a biological phenomenon and not an artefact. Reproducible signals are also required to use CC-EMG as a diagnostic tool for erectile dysfunction. The aim of this study was to a

  3. The ubiquity of mouthings in NGT : a corpus study

    NARCIS (Netherlands)

    Bank, R.

    2015-01-01

    When deaf signers of Sign Language of the Netherlands (NGT, Nederlandse Gebarentaal) sign among themselves, they often combine their signing with moutings: mouthed lexical items from spoken Dutch. Using a corpus of (semi-)spontaneous signing by deaf native signers, this dissertation investigates the

  4. Using the national corpus of russian language in metaphor studies

    Directory of Open Access Journals (Sweden)

    Plisetskaya A. D.

    2010-12-01

    Full Text Available The article describes using The National Corpus of Russian Language for metaphor studies. We analyzed the metaphor 'val'utny koridor' (currency corridor looking into the context of its usage in the media and found out some interesting collocations dealing with the origin of the metaphor. The research can be useful for students learning how to use the national language database.

  5. Semantic Associations in Business English: A Corpus-Based Analysis

    Science.gov (United States)

    Nelson, Mike

    2006-01-01

    This paper examines the semantic associations of words found in the business lexical environment by using a one-million word corpus of both spoken and written Business English. The key method of analysis is that of semantic prosody or semantic association; the notion that words associate with collocates that are themselves related, often either…

  6. Väärtused Theognise luulekogumikus Corpus Theognideum / Martin Suuroja

    Index Scriptorium Estoniae

    Suuroja, Martin

    2002-01-01

    Bibl. lk. 1413-1414. Kokkuvõte "Values in Theognis' collection of poems Corpus Theognideum", lk. 1537-1538. Theognise (552-549) luulekogumiku põhjal analüüsitakse Kreeka ühiskonnas domineerinud väärtusi

  7. Data modelling in corpus linguistics : How low may we go?

    NARCIS (Netherlands)

    van Velzen, Marjolein H.; Nanetti, Luca; de Deyn, Peter P.

    2014-01-01

    Corpus linguistics allows researchers to process millions of words. However, the more words we analyse, i.e., the more data we acquire, the more urgent the call for correct data interpretation becomes. In recent years, a number of studies saw the light attempting to profile some prolific authors' li

  8. How to expand the corpus of spoken English

    Institute of Scientific and Technical Information of China (English)

    张光华

    2015-01-01

    With the speeding up of economic globalization, English as a global language status is becoming more and more manifest.This article from the spoken corpus concept is introduced, combined with the students’ oral English learning methods, guide the students in learning spoken English in different ways to find the effective way to expand the spoken language corpora.

  9. Audio description and corpus analysis of popular music

    NARCIS (Netherlands)

    Van Balen, J.M.H.

    2016-01-01

    In the field of sound and music computing, only a handful of studies are concerned with the pursuit of new musical knowledge. There is a substantial body of corpus analysis research focused on new musical insight, but almost all of it deals with symbolic data: scores, chords or manual annotations. I

  10. A Corpus-based Analysis of English Noun Suffixes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper provides a brief analysis of English suffixes. First, make a classification of the English noun suffixes etymologically; then, obtain the frequencies of each English noun suffixes in sub-corpus FR88 and WSJ88, and last draw a conclusion based on the statistics. That is from the word origins we can see its influences on English vocabulary.

  11. Corpus-based collocation research targeted at Japanese language learners

    Directory of Open Access Journals (Sweden)

    Irena SRDANOVIĆ

    2014-07-01

    Full Text Available This paper discusses corpus-based research on collocations, introduces various tools for querying and extracting Japanese collocations and presents an analysis of Japanese collocations using language corpora and related tools. First, major corpus query tools such as Sketch Engine, NINJAL-NLP, Natsume, Chunagon, which can be used by learners and teachers of Japanese language, are briefly described. Focus then shifts to adjectival and nominal collocates and the resource "Collocation data of adjectives and nouns" which consists of adjective headwords and their nominal collocates extracted from two large corpora, BCCWJ and JpTenTen: 500 adjectives and 9,218 collocate nouns, and 500 adjectives and 23,220 collocate nouns from each corpus respectively. Finally, it is shown that corpus-based resources can be used in the creation of reference materials for learners of the Japanese language. The benefits of empirical research into collocations are also shown by comparing the obtained results with collocations in textbooks for Japanese as foreign language.

  12. Using Corpus Statistics to Remove Redundant Words in Text Categorization.

    Science.gov (United States)

    Yang, Yiming; Wilbur, John

    1996-01-01

    Studies aggressive automated word removal in text categorization in large databases based on corpus statistics to reduce the noise in free texts and to enhance the computational efficiency of categorization. Topics include stop word identification, categorization methods for comparison, tests on four document collections, and evaluation…

  13. Combining text clustering and retrieval for corpus adaptation

    Science.gov (United States)

    He, Feng; Ding, Xiaoqing

    2007-01-01

    The application-relevant text data are very useful in various natural language applications. Using them can achieve significantly better performance for vocabulary selection, language modeling, which are widely employed in automatic speech recognition, intelligent input method etc. In some situations, however, the relevant data is hard to collect. Thus, the scarcity of application-relevant training text brings difficulty upon these natural language processing. In this paper, only using a small set of application specific text, by combining unsupervised text clustering and text retrieval techniques, the proposed approach can find the relevant text from unorganized large scale corpus, thereby, adapt training corpus towards the application area of interest. We use the performance of n-gram statistical language model, which is trained from the text retrieved and test on the application-specific text, to evaluate the relevance of the text acquired, accordingly, to validate the effectiveness of our corpus adaptation approach. The language models trained from the ranked text bundles present well discriminated perplexities on the application-specific text. The preliminary experiments on short message text and unorganized large corpus demonstrate the performance of the proposed methods.

  14. Parkinsonism "Plus" Syndrome With Incidental Corpus Callosal Agenesis

    Directory of Open Access Journals (Sweden)

    Shanbhogue K R

    1999-01-01

    Full Text Available A case of Parkinsonism ′Plus′ syndrome with cranial CT scan and MRI showing corpus callosal agenesis is reported. There were no clinical signs of callosal separation. The causes for the discrepancies between the lack of clinical signs of callosal separation and imaging appearances are discussed. The callosal agenesis is in all probability incidental.

  15. Parkinsonism "Plus" Syndrome With Incidental Corpus Callosal Agenesis

    OpenAIRE

    Shanbhogue K R; Bennett D; Shankar V; Murugesan S; Stephen A S K; Karnan B; Srikanth S

    1999-01-01

    A case of Parkinsonism ′Plus′ syndrome with cranial CT scan and MRI showing corpus callosal agenesis is reported. There were no clinical signs of callosal separation. The causes for the discrepancies between the lack of clinical signs of callosal separation and imaging appearances are discussed. The callosal agenesis is in all probability incidental.

  16. How to expand the corpus of spoken English

    Institute of Scientific and Technical Information of China (English)

    张光华

    2015-01-01

    With the speeding up of economic globalization, English as a global language status is becoming more and more manifest.This article from the spoken corpus concept is introduced, combined with the students' oral English learning methods, guide the students in learning spoken English in different ways to find the effective way to expand the spoken language corpora.

  17. A Corpus of Images and Text in Online News

    NARCIS (Netherlands)

    Hollink, L.; Bedjeti, A.; Harmelen, M. van; Elliott, D.

    2016-01-01

    In recent years, several datasets have been released that include images and text, giving impulse to new methods that combine natural language processing and computer vision. However, there is a need for datasets of images in their natural textual context. The ION corpus contains 300K news article

  18. Learning unification-based grammars using the Spoken English Corpus

    CERN Document Server

    Osborne, M; Osborne, Miles; Bridge, Derek

    1994-01-01

    This paper describes a grammar learning system that combines model-based and data-driven learning within a single framework. Our results from learning grammars using the Spoken English Corpus (SEC) suggest that combined model-based and data-driven learning can produce a more plausible grammar than is the case when using either learning style isolation.

  19. A Corpus Study of Negative Imperatives in Natural Language Instructions

    CERN Document Server

    Linden, K V; Linden, Keith Vander; Eugenio, Barbara Di

    1996-01-01

    In this paper, we define the notion of a preventative expression and discuss a corpus study of such expressions in instructional text. We discuss our coding schema, which takes into account both form and function features, and present measures of inter-coder reliability for those features. We then discuss the correlations that exist between the function and the form features.

  20. You Should Have the Body: Understanding Habeas Corpus

    Science.gov (United States)

    Landman, James

    2008-01-01

    English legal commentator William Blackstone described the writ of habeas corpus as a second Magna Carta, and Supreme Court Chief Justice John Marshall called it the "great writ." It has been part of the Anglo-American common law tradition since the Middle Ages. In the United States, it has been a source of tension between state and federal…

  1. A Corpus-Based Comparative Study of "Learn" and "Acquire"

    Science.gov (United States)

    Yang, Bei

    2016-01-01

    As an important yet intricate linguistic feature in English language, synonymy poses a great challenge for second language learners. Using the 100 million-word British National Corpus (BNC) as data and the software Sketch Engine (SkE) as an analyzing tool, this article compares the usage of "learn" and "acquire" used in natural…

  2. EuroGOV: Engineering a Multilingual Web Corpus

    NARCIS (Netherlands)

    Sigurbjörnsson, B.; Kamps, J.; de Rijke, M.

    2005-01-01

    EuroGOV is a multilingual web corpus that was created to serve as the document collection for WebCLEF, the CLEF 2005 web retrieval task. EuroGOV is a collection of web pages crawled from the European Union portal, European Union member state governmental web sites, and Russian government web sites.

  3. Immune Regulation of the Corpus Luteum: A Short Review

    Institute of Scientific and Technical Information of China (English)

    N.A.Andino; A.J.Machado

    1992-01-01

    Recent clinieal and basic studies indicate a role of cytokines in the femate reproductive processes. In tiffs art iclc we review the classical and more advanced literature on cellular immune responses and corpus luteum function and recent evidences of the importance of cytokines on the function and life span of this organ.

  4. [Effects of callosotomy in the treatment of intractable epilepsies in children on psychiatric disorders].

    Science.gov (United States)

    Septien, L; Giroud, M; Sautreaux, J L; Brenot, M; Marin, A; Dumas, R; Nivelon, J L

    1992-01-01

    Two children, 13 and 14 years old, presented an intractable epilepsy of Lennox-Gastaut. In front of dangerous tonic and atonic epileptic crisis, a corpus callosotomy was performed. Corpus callosotomy is becoming a more widely used procedure in the treatment of intractable epilepsy as Lennox-Gastaut syndrome, or frontal epilepsy. However, there have been very few series that have reported results in children. It is not a complete but a partial, callosal section including approximately the anterior two thirds of the callosum. After this surgery the two children improved dramatically because the dangerous tonic and atonic crisis disappeared. Secondly we observed improvement of pre-surgical psychiatric troubles, that is a data not developed in the literature. Before surgery, the two children had a frontal syndrome with hyperkinesia, distractibility, aggressiveness, alexithymia, loss of the program of ideas. During the two months after the section of the anterior two thirds of the corpus callosum, we observed a progressive improvement of the frontal syndrome, with possibility to learn new praxies. The intellectual quotient was not altered and associative functions, depending of the posterior third of the corpus callosum were spared. Anti-epileptic medications were not stopped. We think that the improvement of the frontal syndrome is due to reduction of seizures. Therefore, we insist on the interest of the section of the anterior two thirds of the corpus callosum as treatment of tonic and atonic seizures but also as treatment of psychiatric symptoms depending of a frontal syndrome.

  5. Evaluating Corpus Literacy Training for Pre-Service Language Teachers: Six Case Studies

    Science.gov (United States)

    Heather, Julian; Helt, Marie

    2012-01-01

    Corpus literacy is the ability to use corpora--large, principled databases of spoken and written language--for language analysis and instruction. While linguists have emphasized the importance of corpus training in teacher preparation programs, few studies have investigated the process of initiating teachers into corpus literacy with the result…

  6. 76 FR 49285 - Amendment of Class D Airspace; Corpus Christi, TX

    Science.gov (United States)

    2011-08-10

    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class D Airspace; Corpus Christi, TX AGENCY... Register June 2, 2011, ] amending Class D airspace at Cabaniss Navy Outlying Field (NOLF), Corpus Christi... Cabaniss NOLF, Corpus Christi, TX (76 FR 31821, Docket No. FAA-2010-1171). Subsequent to publication,...

  7. 26 CFR 1.661(a)-1 - Estates and trusts accumulating income or distributing corpus; general.

    Science.gov (United States)

    2010-04-01

    ... distributing corpus; general. 1.661(a)-1 Section 1.661(a)-1 Internal Revenue INTERNAL REVENUE SERVICE... Accumulate Income Or Which Distribute Corpus § 1.661(a)-1 Estates and trusts accumulating income or distributing corpus; general. Subpart C, part I, subchapter J, chapter 1 of the Code, is applicable to...

  8. 76 FR 31821 - Amendment of Class D Airspace; Corpus Christi, TX

    Science.gov (United States)

    2011-06-02

    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class D Airspace; Corpus Christi, TX AGENCY... amends Class D airspace within the Corpus Christi, TX, area by updating the geographic coordinates for... the geographic coordinates, within Class D airspace, of the Cabaniss NOLF, Corpus Christi, TX,...

  9. 40 CFR 81.136 - Corpus Christi-Victoria Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Corpus Christi-Victoria Intrastate Air... Air Quality Control Regions § 81.136 Corpus Christi-Victoria Intrastate Air Quality Control Region. The Corpus Christi-Victoria Intrastate Air Quality Control Region (Texas) consists of the...

  10. 26 CFR 1.643(b)-2 - Dividends allocated to corpus.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Dividends allocated to corpus. 1.643(b)-2... to corpus. Extraordinary dividends or taxable stock dividends which the fiduciary, acting in good faith, determines to be allocable to corpus under the terms of the governing instrument and...

  11. Motivating College Students' Learning English for Specific Purposes Courses through Corpus Building

    Science.gov (United States)

    Wu, Lin-Fang

    2014-01-01

    This study was conducted to determine how to motivate technical college students to learn English for specific purposes (ESP) courses through corpus building and enhance their language proficiency during the coursework for their majors. This study explores corpus building skills, how to simplify ESP courses by corpus building for English as second…

  12. Integrating Corpus Work into Secondary Education: From Data-Driven Learning to Needs-Driven Corpora

    Science.gov (United States)

    Braun, Sabine

    2007-01-01

    This paper reports on an empirical case study conducted to investigate the overall conditions and challenges of integrating corpus materials and corpus-based learning activities into English-language classes at a secondary school in Germany. Starting from the observation that in spite of the large amount of research into corpus-based language…

  13. Corpus-Based Research and Pedagogy in EAP: From Lexis to Genre

    Science.gov (United States)

    Flowerdew, Lynne

    2015-01-01

    This plenary paper showcases current corpus-based research on written academic English, illustrating the tight links that exist between corpus research and pedagogic applications. I first explicate Sinclair's concept of the "lexical approach", which underpins much corpus research and pedagogy. I then discuss studies which focus on…

  14. 大脑前动脉供血区梗死的临床特征%Analysis of the clinical characteristics in patients with anterior cerebral artery territory infarction

    Institute of Scientific and Technical Information of China (English)

    葛颂; 沈飞飞; 程虹; 万琪

    2013-01-01

    Objective To investigate the risk factors,etiologies,mechanisms,clinical features and imaging characteristics of anterior cerebral artery (ACA) territory infarction in Chinese patients. Methods The clinical and neuroradiological data of the patients with acute ACA territory infarction were reviewed retrospectively. The risk factors,etiologies,distributions of infarct lesions,and clinical manifestations of the patients were summarized. The distribution of infarct lesions and clinical manifestations of an embolization group (cardiogenic or carotid artery embolism) and an intrinsic ACA atherosclerosis group were compared. The mechanisms underlying stroke in intrinsic ACA atherosclerosis group were analyzed. Results ACA territory infarction was found in 58 cases ,accounting for 6.9% of the total acute ischemic stroke during the same hospitalization period. A total of 52 patients with ACA infarction undertaking both intracranial and extracranial artery investigation were included. The most common risk factor was hypertension ( 80.8% ). Stroke subtypes included cardioembolic infarction in 6 patients( 9.6% ) ,atherothrombotic infarction in 45 ( 86.5% ) ,and infarction of unknown cause in 2 ( 3.8% ). The corpus callosum was involved in 6 ( 37.% ) and 26 ( 86.7% ) in the embolization group ( 16/52 ,30.8% ) and the intrinsic ACA atherosclerosis group (30/52,57.7%),respectively (χ2=9.705,P=0.002). The territory beyond ACA was involved in 8 (50.0%) and 2 (6.7%) respectively (χ2=9.111,P=.003). There were 19 (63.3%) patients with hypobulia/apathy in intrinsic ACA atherosclerosis group,and 5 (31.3%) in the embolization group (χ2=4.305,P=0.038). There were no significant differences in other manifestations between two groups (P>0.05). A2 stenosis or occlusion was observed in 23 (23/30,76.7%) patients in intrinsic ACA atherosclerosis group ,including local branch occlusion (n= 12),in situ thrombotic occlusion (n=5),artery-to-artery embolism (n=5),and combination of local branch

  15. The role of GPR1 signaling in mice corpus luteum.

    Science.gov (United States)

    Yang, Ya-Li; Ren, Li-Rong; Sun, Li-Feng; Huang, Chen; Xiao, Tian-Xia; Wang, Bao-Bei; Chen, Jie; Zabel, Brian A; Ren, Peigen; Zhang, Jian V

    2016-07-01

    Chemerin, a chemokine, plays important roles in immune responses, inflammation, adipogenesis, and carbohydrate metabolism. Our recent research has shown that chemerin has an inhibitory effect on hormone secretion from the testis and ovary. However, whether G protein-coupled receptor 1 (GPR1), the active receptor for chemerin, regulates steroidogenesis and luteolysis in the corpus luteum is still unknown. In this study, we established a pregnant mare serum gonadotropin-human chorionic gonadotropin (PMSG-hCG) superovulation model, a prostaglandin F2α (PGF2α) luteolysis model, and follicle and corpus luteum culture models to analyze the role of chemerin signaling through GPR1 in the synthesis and secretion of gonadal hormones during follicular/luteal development and luteolysis. Our results, for the first time, show that chemerin and GPR1 are both differentially expressed in the ovary over the course of the estrous cycle, with highest levels in estrus and metestrus. GPR1 has been localized to granulosa cells, cumulus cells, and the corpus luteum by immunohistochemistry (IHC). In vitro, we found that chemerin suppresses hCG-induced progesterone production in cultured follicle and corpus luteum and that this effect is attenuated significantly by anti-GPR1 MAB treatment. Furthermore, when the phosphoinositide 3-kinase (PI3K) pathway was blocked, the attenuating effect of GPR1 MAB was abrogated. Interestingly, PGF2α induces luteolysis through activation of caspase-3, leading to a reduction in progesterone secretion. Treatment with GPR1 MAB blocked the PGF2α effect on caspase-3 expression and progesterone secretion. This study indicates that chemerin/GPR1 signaling directly or indirectly regulates progesterone synthesis and secretion during the processes of follicular development, corpus luteum formation, and PGF2α-induced luteolysis.

  16. Mitos clásicos en el teatro del Caribe. Esbozo y sistematización de un corpus

    Directory of Open Access Journals (Sweden)

    Gustavo Herrera Díaz

    2014-04-01

    Full Text Available P { margin-bottom: 0.21cm; }A:link { } Resumen: En la última década del siglo XX y a principios del siglo XXI, con la realización de algunos congresos y estudios académicos, se ha comenzado a valorar la presencia de los mitos clásicos en el teatro iberoamericano. Ello ha posibilitado el rescate y análisis de un creciente e importante corpus de obras que continuamente se actualiza con nuevas puestas en escena y enfoques. Una línea de investigación valiosa al respecto ha sido la de intentar sistematizar, desde múltiples métodos y teorías, todo el repertorio encontrado. Los estudios de Costa Palamides y Elina Miranda, por mencionar algunos de los más conocidos, son valiosos aportes a este propósito. En este marco se inserta el presente trabajo que, partiendo de estudios anteriores y del rastreo de nuevas producciones dramáticas, aspira contribuir a la actualización y sistematización del corpus caribeño existente, así como revelar nuevas tendencias. Nos enfocamos especialmente en las obras de las Antillas hispanas, puestas en relación con las producidas en otras áreas del Caribe.

  17. Using Google as a Super Corpus to Drive Written Language Learning: A Comparison with the British National Corpus

    Science.gov (United States)

    Sha, Guoquan

    2010-01-01

    Data-driven learning (DDL), or corpus-based language learning, involves the learner in an exploratory task to discover appropriate expressions or collocates regarding his writing. However, the problematic units of meaning in each learner's writing are so diverse that conventional corpora often prove futile. The search engine Google with the…

  18. Formulaic Language and Collocations in German Essays: From Corpus-Driven Data to Corpus-Based Materials

    Science.gov (United States)

    Krummes, Cedric; Ensslin, Astrid

    2015-01-01

    Whereas there exists a plethora of research on collocations and formulaic language in English, this article contributes towards a somewhat less developed area: the understanding and teaching of formulaic language in German as a foreign language. It analyses formulaic sequences and collocations in German writing (corpus-driven) and provides modern…

  19. 76 FR 18395 - Safety Zone; Naval Air Station Corpus Christi Air Show, Oso Bay, Corpus Christi, TX

    Science.gov (United States)

    2011-04-04

    ... and the fact the no commercial entities and very few recreational fisherman utilize this section of...: The owners or operators of vessels intending to transit the affected waterway during the time of... Corpus Christi or a designated representative. (2) Persons and vessels desiring to enter, transit...

  20. 33 CFR 3.40-35 - Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sector Corpus Christi Marine... ZONES, AND CAPTAIN OF THE PORT ZONES Eighth Coast Guard District § 3.40-35 Sector Corpus Christi Marine Inspection Zone and Captain of the Port Zone. Sector Corpus Christi's office is located in Corpus Christi,...

  1. Corpus Use and Learning to Translate, almost 20 years on

    Directory of Open Access Journals (Sweden)

    Patricia Rodríguez-Inés

    2016-06-01

    Full Text Available It is almost 20 years since a series of conferences known as CULT (Corpus Use and Learning to Translate started. The first and second took place in Bertinoro, Italy, back in 1997 and 2000, respectively. The third was held in 2004 in Barcelona, and the fourth in 2015 in Alicante. Each was organized by a few enthusiastic lecturers and scholars who also happened to be corpus lovers. Guy Aston, Silvia Bernardini, Dominic Stewart and Federico Zanettin, from the Universitá di Bologna; Allison Beeby, Patricia Rodríguez-Inés and Pilar Sánchez-Gijón, from the Universitat Autònoma de Barcelona; and Daniel Gallego-Hernández, from the Universidad de Alicante, organized CULT conferences in the belief that spreading the word about the usefulness of corpora for teaching and professional translation purposes would have positive results.

  2. Consultation de corpus et styles d'apprentissage.

    OpenAIRE

    Boulton, Alex

    2010-01-01

    Les corpus représentent une ressource avec de multiples possibilités pour l’apprentissage des langues, mais les résultats d’expériences avec les étudiants sont moins convaincants qu’on pourrait l’espérer. Une explication serait que les résultats quantitatifs cachent la diversité des profils d’apprenants. Cette étude décrit une expérience où des étudiants en architecture consultent soit un corpus, soit un dictionnaire pour résoudre des difficultés précises d’usage en anglais, et complètent un ...

  3. Corpus linguistics at the service of English teachers

    Directory of Open Access Journals (Sweden)

    Leonardo Juliano Recski

    2006-01-01

    Full Text Available This paper contemplates how corpus evidence might be used to address teachers' questions about English grammar and suggests that corpus linguistics has an important role to play in raising their awareness to linguistic features and patterns. The article surveys a range of grammatical questions posted by EFL/ESL teachers on four Orkut communities devoted to the teaching and learning of English. It concentrates on three specific types of questions: synonymous lexical items which function differently and are reported to be difficult to teach and explain; linguistic evidence that contradicts the prescriptive grammar rules that teachers have been taught during their education; and collocations that teachers attempt to explicate. In attempting to address the teachers' questions, corpus evidence is used to offer possible explanations. It is suggested that the use of corpus data in addressing these questions is not only convincing but also leads to discoveries of patterns and meanings which might not be found in other reference materials such as grammars and dictionariesEste artículo contempla cómo la evidencia del corpus lingüístico podría ser usado para responder preguntas de los profesores de inglés respecto de la gramática inglesa, y sugiere que el corpus lingüístico tiene un rol importante que jugar para incrementar la advertencia respecto de los patrones y aspectos lingüísticos. El artículo describe una selección de preguntas en torno a gramática inglesa enviadas por profesores de inglés como idioma extranjero y como segunda lengua en cuatro comunidades Orkut dedicados a la enseñanza y aprendizaje del idioma inglés. El artículo se concentra en tres tipos específicos de preguntas: ítemes léxicos sinónimos que funcionan de manera diferente y se reportan como difíciles para enseñar y explicar; evidencia lingüística que contradice las reglas de la gramática prescriptiva, la cual se ha enseñado a los profesores de Ingl

  4. Cholesterol transport and steroidogenesis by the corpus luteum

    Directory of Open Access Journals (Sweden)

    Christenson Lane K

    2003-11-01

    Full Text Available Abstract The synthesis of progesterone by the corpus luteum is essential for the establishment and maintenance of early pregnancy. Regulation of luteal steroidogenesis can be broken down into three major events; luteinization (i.e., conversion of an ovulatory follicle, luteal regression, and pregnancy induced luteal maintenance/rescue. While the factors that control these events and dictate the final steroid end products are widely varied among different species, the composition of the corpus luteum (luteinized thecal and granulosa cells and the enzymes and proteins involved in the steroidogenic pathway are relatively similar among all species. The key factors involved in luteal steroidogenesis and several new exciting observations regarding regulation of luteal steroidogenic function are discussed in this review.

  5. Academic lexis and disciplinary practice: corpus evidence for specificity

    Directory of Open Access Journals (Sweden)

    Ken Hyland

    2009-12-01

    Full Text Available The presence of unfamiliar words and expressions in academic texts is a serious obstacle to students reading in a second language. EAP has responded to this challenge by taking the view that there is a common core of academic vocabulary which is frequent across an academic register. This paper briefly considers this view by examining the range, frequency, collocation, and meaning of items on the Academic Word List (AWL in a large multidisciplinary corpus. Our corpus analysis shows that individual lexical items on the list often occur and behave in different ways across disciplines and that words commonly contribute to ‘lexical bundles’ which also reflect disciplinary preferences. Our findings question the widely held assumption that there is a single core vocabulary needed for academic study and suggests that teachers should assist students towards developing a more restricted, disciplinary-based lexical repertoire.

  6. The CLEF corpus: semantic annotation of clinical text.

    Science.gov (United States)

    Roberts, Angus; Gaizauskas, Robert; Hepple, Mark; Davis, Neil; Demetriou, George; Guo, Yikun; Kola, Jay; Roberts, Ian; Setzer, Andrea; Tapuria, Archana; Wheeldin, Bill

    2007-10-11

    The Clinical E-Science Framework (CLEF) project is building a framework for the capture, integration and presentation of clinical information: for clinical research, evidence-based health care and genotype-meets-phenotype informatics. A significant portion of the information required by such a framework originates as text, even in EHR-savvy organizations. CLEF uses Information Extraction (IE) to make this unstructured information available. An important part of IE is the identification of semantic entities and relationships. Typical approaches require human annotated documents to provide both evaluation standards and material for system development. CLEF has a corpus of clinical narratives, histopathology reports and imaging reports from 20 thousand patients. We describe the selection of a subset of this corpus for manual annotation of clinical entities and relationships. We describe an annotation methodology and report encouraging initial results of inter-annotator agreement. Comparisons are made between different text sub-genres, and between annotators with different skills.

  7. A Corpus-Based Investigation of Definite Description Use

    CERN Document Server

    Poesio, M; Poesio, Massimo; Vieira, Renata

    1997-01-01

    We present the results of a study of definite descriptions use in written texts aimed at assessing the feasibility of annotating corpora with information about definite description interpretation. We ran two experiments, in which subjects were asked to classify the uses of definite descriptions in a corpus of 33 newspaper articles, containing a total of 1412 definite descriptions. We measured the agreement among annotators about the classes assigned to definite descriptions, as well as the agreement about the antecedent assigned to those definites that the annotators classified as being related to an antecedent in the text. The most interesting result of this study from a corpus annotation perspective was the rather low agreement (K=0.63) that we obtained using versions of Hawkins' and Prince's classification schemes; better results (K=0.76) were obtained using the simplified scheme proposed by Fraurud that includes only two classes, first-mention and subsequent-mention. The agreement about antecedents was al...

  8. Capture of Public Servant. Requirements and Substantial habeas corpus

    Directory of Open Access Journals (Sweden)

    Carlos Arturo Gómez Pavajeau

    2015-06-01

    Full Text Available The capture of the public servant in a criminal investigation is subject to special rules and different to those for the capture of individuals, since the imprisonment of an official can affect continuity, speed and efficiency of the civil service, an equally important constitutional value. Therefore, as a rule capturing the public servant must be preceded by a request for suspensión by the prosecution, and to proceed without suspension, the prosecutor in his providence should motivate the reasons and arguments why not affects the normal functioning of public administration. The lack of motivation for this essential aspect, affords a fact that becomes appropriate procedural habeas corpus as an effective mechanism guarantees of personal freedom. Similarly appropriate habeas corpus when catching public server ordered by a prosecutor without functional competence to advance research, by setting a path made by organic defect.

  9. MORPOHOLOGICAL POS TAGGING IN ORAL LANGUAGE CORPUS: CHALLENGES FOR AELIUS

    Directory of Open Access Journals (Sweden)

    Gabriel de Ávila Othero

    2014-12-01

    Full Text Available In this paper, we present the results of our work with automatic morphological annotation of excerpts from a corpus of spoken language – belonging to the VARSUL project – using the free morphosyntatic tagger Aelius. We present 20 texts containing 154,530 words, annotated automatically and corrected manually. This paper presents the tagger Aelius and our work of manual review of the texts, as well as our suggestions for improvements of the tool, concerning aspects of oral texts. We verify the performance of morphosyntactic tagging a spoken language corpus, an unprecedented challenge for the tagger. Based on the errors of the tagger, we try to infer certain patterns of annotation to overcome limitations presented by the program, and we propose suggestions for implementations in order to allow Aelius to tag spoken language corpora in a more effective way, specially treating cases such as interjections, apheresis, onomatopeia and conversational markers.

  10. Corpus Linguistics, Network Analysis and Co-occurrence Matrices Corpus Linguistics, Network Analysis and Co-occurrence Matrices

    Directory of Open Access Journals (Sweden)

    Keith Stuart

    2009-12-01

    Full Text Available This article describes research undertaken in order to design a methodology for the reticular representation of knowledge of a specific discourse community. To achieve this goal, a representative corpus of the scientific production of the members of this discourse community (Universidad Politécnica de Valencia, UPV was created. The article presents the practical analysis (frequency, keyword, collocation and cluster analysis that was carried out in the initial phases of the study aimed at establishing the theoretical and practical background and framework for our matrix and network analysis of the scientific discourse of the UPV. In the methodology section, the processes that have allowed us to extract from the corpus the linguistic elements needed to develop co-occurrence matrices, as well as the computer tools used in the research, are described. From these co-occurrence matrices, semantic networks of subject and discipline knowledge were generated. Finally, based on the results obtained, we suggest that it may be viable to extract and to represent the intellectual capital of an academic institution using corpus linguistics methods in combination with the formulations of network theory.En este artículo describimos la investigación que se ha desarrollado en el diseño de una metodología para la representación reticular del conocimiento que se genera en el seno de una institución a partir de un corpus representativo de la producción científica de los integrantes de dicha comunidad discursiva, la Universidad Politécnica de Valencia.. Para ello, presentamos las acciones que se realizaron en las fases iniciales del estudio encaminadas a establecer el marco teórico y práctico en el que se inscribe nuestro análisis. En la sección de metodología se describen las herramientas informáticas utilizadas, así como los procesos que nos permitieron disponer de aquellos elementos presentes en el corpus, que nos llevarían al desarrollo de

  11. Corpus Luteum Cyst Rupture - US Findings and Clinical Features

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Shang Hun; Lee, Jong Hwa; Kang, Byeong Seong; Yang, Myeon Jun; Jeong, Yoong Ki [Ulsan University Hospital, Ulsan (Korea, Republic of); Kim, Yong Hwan [Dongsan Medical Center, Keimyung University College of Medicine, Daegu (Korea, Republic of); Lee, Jae Hung [Dong Kang General Hospital, Ulsan (Korea, Republic of)

    2006-09-15

    To describe the US findings of corpus luteum cyst rupture in order to elucidate the associated clinical features. Twenty patients with proven corpus luteum cyst rupture were included in this study. The US findings of these patients were retrospectively analyzed in terms of the presence of designable cyst, size of the cyst, thickness and blood flow of the cyst wall, extension and echogenicity of peritoneal fluid, and involved site (right or left ovary). We also surveyed the clinical features such as the onset period according to the menstrual cycle, and the presence of suspectable cause. Fourteen of the 20 patients revealed designable cysts (mean diameter of 2.6 cm) with thick walled cysts (mean thickness, 4.6 mm, 2.4-6.8 mm) and increased blood flow. Six patients didn't reveal any cyst but only hematoma in adnexa. All patients had hemoperitoneum in the pelvic cavity, and the hemoperitoneum was extended to Morrison's pouch in 8 patients and to the subphrenic space in 6. The cysts occurred in the right adnexa in 15 patients and in the left in 5. Mean interval from the last menstrual period (LMP) was 26 days (13-44 days) and 6 of the 8 patients for whom it had been possible to obtain detailed history taking had had coitus just before the occurrence of symptom. When women who are hospitalized for acute abdomen and who are in luteal phase reveal US findings of hematoma or thick-walled cyst in adnexa and hemoperitoneum, a corpus luteum cyst rupture is highly suspected. In our case study the corpus luteum cyst rupture predominantly occurred in the right side, and the most suspectable cause was trauma such as coitus in the luteal phase

  12. LAS PERTURBACIONES MENTALES EN EL CORPUS HIPPOCRATICUM. EL CONCEPTO "MANIA"

    OpenAIRE

    MARTINEZ CONESA, J.A.

    1991-01-01

    LA MEDICINA HIPOCRATICA MUESTRA GRAN INTERES POR LOS ESTADOS PATOLOGICOS DE LA MENTE. EL CORPUS HIPPOCRATICUM UTILIZA UNA AMPLIA GAMA DE LOCUCIONES PARA EXPRESAR LOS TRASTORNOS MENTALES, TANTO LOS DE CARACTER TRANSITORIO COMO LOS PERMANENTES O CRONICOS. EN GENERAL, LOS AUTORES CONTINUAN APLICANDO TERMINOS USADOS YA EN LA TRAGEDIA GRIEGA, AUNQUE APORTAN LA ORIGINALIDAD DE LA CREACION DE ALGUNOS NEOLOGISMOS, COMO EL TERMINO "FRENITIS", CON UN SENTIDO ESPECIFICO MEDICO. ENTRE LOS TERMINOS EMPLEA...

  13. A Corpus-based Study of Temporal Signals

    CERN Document Server

    Derczynski, Leon

    2012-01-01

    Automatic temporal ordering of events described in discourse has been of great interest in recent years. Event orderings are conveyed in text via va rious linguistic mechanisms including the use of expressions such as "before", "after" or "during" that explicitly assert a temporal relation -- temporal signals. In this paper, we investigate the role of temporal signals in temporal relation extraction and provide a quantitative analysis of these expres sions in the TimeBank annotated corpus.

  14. Corpus de inscripciones sobre la esclavitud infantil en Hispania romana

    OpenAIRE

    Crespo Ortiz de Zárate, Santos

    2009-01-01

    Se presenta en este trabajo el corpus epigráfico relativo a la servidumbre infantil en Hispania romana, como base a una serie de estudios sobre la dependencia personal en este ámbito social. This work shows the epigraphic sources dealing with the children-slaves in Roman Spain and sets up a base for future studies about personal dependence in this social sphere.

  15. Fibrosis of corpus cavernosum in animals following cavernous nerve ablation

    Institute of Scientific and Technical Information of China (English)

    Wan-LiHu; Li-QuanHu; jianSong; Shi-WenLi; Xin-MinZheng; BeiCheng; Bing-ChunTian

    2004-01-01

    t Aim: To investigate alterations of smooth muscle cells and collagen fibers in corpus cavernosum following cavernous neurectomy and its relation to the expression of transforming growth factor-β1 (TGF-β1). Methods: Ten adult male SD rats (neurectomy group) were subject to a bilateral cavernous nerve (CN) resection aseptically under an operating microscope, with 6 sham-operated rats as the control. Fifteen weeks after the operation, the penile specimens were collected and prepared for quantitative-analyzing of ratio of smooth muscle to collagen fibers in corpus cavernosum with confocal microscopy, and for detecting the expression of TGF-β1 by RT-PCR and westernblot.Results: Smooth muscle cells that show red color after fluorescent-labeling with tetramethylrhodamine isothiocyanatephalloidin and collagen fibers that produce green autofluorescence after paraformaldehyde fixation were clearly identified under the confocal microscope. Quantification of fluorescent intensity showed that the ratio of smooth muscle to collagen fibers in corpus cavernosum in neurectomy group was 0.265± 0.125, which was significantly lower than that in sham-operated group (0.760±0.196, P<0.01). RT-PCR and western-blot analyses revealed a significantlyhigher expression of TGF-β1 in the penile tissues of the neurectomy animals than that in sham-operated group.Conclusion: Bilateral ablation of CN can lead to fibrosis of corpus cavernosum, which may be related to an increased expression of TGF-β1 induced by hypoxia in cavernous tissue after denervation.

  16. Corpus annotation for mining biomedical events from literature

    Directory of Open Access Journals (Sweden)

    Tsujii Jun'ichi

    2008-01-01

    Full Text Available Abstract Background Advanced Text Mining (TM such as semantic enrichment of papers, event or relation extraction, and intelligent Question Answering have increasingly attracted attention in the bio-medical domain. For such attempts to succeed, text annotation from the biological point of view is indispensable. However, due to the complexity of the task, semantic annotation has never been tried on a large scale, apart from relatively simple term annotation. Results We have completed a new type of semantic annotation, event annotation, which is an addition to the existing annotations in the GENIA corpus. The corpus has already been annotated with POS (Parts of Speech, syntactic trees, terms, etc. The new annotation was made on half of the GENIA corpus, consisting of 1,000 Medline abstracts. It contains 9,372 sentences in which 36,114 events are identified. The major challenges during event annotation were (1 to design a scheme of annotation which meets specific requirements of text annotation, (2 to achieve biology-oriented annotation which reflect biologists' interpretation of text, and (3 to ensure the homogeneity of annotation quality across annotators. To meet these challenges, we introduced new concepts such as Single-facet Annotation and Semantic Typing, which have collectively contributed to successful completion of a large scale annotation. Conclusion The resulting event-annotated corpus is the largest and one of the best in quality among similar annotation efforts. We expect it to become a valuable resource for NLP (Natural Language Processing-based TM in the bio-medical domain.

  17. Exemplar-based visualization of large document corpus.

    Science.gov (United States)

    Chen, Yanhua; Wang, Lijun; Dong, Ming; Hua, Jing

    2009-01-01

    With the rapid growth of the World Wide Web and electronic information services,text corpus is becoming available on-line at an incredible rate.By displaying text data in a logical layout (e.g., color graphs),text visualization presents a direct way to observe the documents as well as understand the relationship between them.In this paper, we propose a novel technique, Exemplar-based Visualization (EV), to visualize an extremely large text corpus. Capitalizing on recent advances in matrix approximation and decomposition, EV presents a probabilistic multidimensional projection model in the low-rank text subspace with a sound objective function. The probability of each document proportion to the topics is obtained through iterative optimization and embedded to a low dimensional space using parameter embedding.By selecting the representative exemplars, we obtain a compact approximation of the data. This makes the visualization highly efficient and flexible. In addition, the selected exemplars neatly summarize the entire data set and greatly reduce the cognitive overload in the visualization, leading to an easier interpretation of large text corpus. Empirically, we demonstrate the superior performance of EV through extensive experiments performed on the publicly available text data sets.

  18. The Short Infinitive in Slovene: A Corpus-based Approach

    Directory of Open Access Journals (Sweden)

    Sara Može

    2013-05-01

    Full Text Available The article presents the results of an in-depth, corpus-based study on the use of the short and long infinitive in Slovene. After a few introductory remarks followed by a brief theoretical overview of the topic, a categorised list of problematic infinitive structures based upon a previously performed analysis of Šolar, a corpus of student texts, is provided. Šolar’s data gave insight into the whole range of linguistic problems associated with the use of two forms and allowed for the subject of the study, i.e. ‘full verb + infinitival complement’ structures, to be precisely defined. The following section describes the method used to compile a shortlist of high-frequency full verbs co-occurring with infinitival complements from the half-million-word, morphosyntactically and syntactically annotated training corpus that was created within the Communication in Slovene project. Finally, the co-relation between genre, mode and the use of the two forms is examined in detail; based on a quantitative analysis of data extracted from corpora of written (FidaPLUS and spoken language (GOS for each full verb on the shortlist, new findings on the actual use of the short and long infinitive in both written and spoken texts are presented.

  19. Anterior cruciate ligament - updating article.

    Science.gov (United States)

    Luzo, Marcus Vinicius Malheiros; Franciozi, Carlos Eduardo da Silveira; Rezende, Fernando Cury; Gracitelli, Guilherme Conforto; Debieux, Pedro; Cohen, Moisés

    2016-01-01

    This updating article on the anterior cruciate ligament (ACL) has the aim of addressing some of the most interesting current topics in this field. Within this stratified approach, it contains the following sections: ACL remnant; anterolateral ligament and combined intra and extra-articular reconstruction; fixation devices; and ACL femoral tunnel creation techniques.

  20. Anterior cruciate ligament - updating article

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Malheiros Luzo

    2016-08-01

    Full Text Available ABSTRACT This updating article on the anterior cruciate ligament (ACL has the aim of addressing some of the most interesting current topics in this field. Within this stratified approach, it contains the following sections: ACL remnant; anterolateral ligament and combined intra and extra-articular reconstruction; fixation devices; and ACL femoral tunnel creation techniques.

  1. Recent Developments in Corpus Linguistics and Corpus-Based Research/Department of Linguistics and Modern Language Studies at the Hong Kong Institute of Education

    Science.gov (United States)

    Xie, Qin

    2015-01-01

    Corpus linguistics has transformed the landscape of empirical research on languages in recent decades. The proliferation of corpus technology has enabled researchers worldwide to conduct research in their own geographical locations with few hindrances. It has become increasingly commonplace for researchers to compile their own corpora for specific…

  2. Influence of pregnancy and labor on the occurrence of nerve fibers expressing the capsaicin receptor TRPV1 in human corpus and cervix uteri

    Directory of Open Access Journals (Sweden)

    Irestedt Lars

    2008-02-01

    Full Text Available Abstract Background Cervical ripening is a prerequisite for a normal obstetrical outcome. This process, including labor, is a painful event that shares features with inflammatory reactions where peripheral nociceptive pathways are involved. The capsaicin and heat receptor TRPV1 is a key molecule in sensory nerves involved in peripheral nociception, but little is known regarding its role in the pregnant uterus. Therefore, the aim of this study was to investigate human corpus and cervix uteri during pregnancy and labor and non-pregnant controls for the presence of TRPV1. Methods We have investigated human uterine corpus and cervix biopsies at term pregnancy and parturition. Biopsies were taken from the upper edge of the hysterotomy during caesarean section at term (n = 8, in labor (n = 8 and from the corresponding area in the non-pregnant uterus after hysterectomy (n = 8. Cervical biopsies were obtained transvaginally from the anterior cervical lip. Serial frozen sections were examined immunohistochemically using specific antibodies to TRPV1 and nerve markers (neurofilaments/peripherin. Results In cervix uteri, TRPV1-immunoreactive fibers were scattered throughout the stroma and around blood vessels, and appeared more frequent in the sub-epithelium. Counts of TRPV1-immunoreactive nerve fibers were not significantly different between the three groups. In contrast, few TRPV1-immunoreactive fibers were found in nerve fascicles in the non-pregnant corpus, and none in the pregnant corpus. Conclusion In this study, TRPV1 innervation in human uterus during pregnancy and labor is shown for the first time. During pregnancy and labor there was an almost complete disappearance of TRPV1 positive nerve fibers in the corpus. However, cervical innervation remained throughout pregnancy and labor. The difference in TRPV1 innervation between the corpus and the cervix is thus very marked. Our data suggest that TRPV1 may be involved in pain mechanisms associated with

  3. HACIA LA CONSTITUCIÓN DE UN CORPUS DIACRÓNICO DEL ESPAÑOL DE CHILE TOWARDS CHILEAN SPANISH LANGUAGE DIACHRONIC CORPUS

    Directory of Open Access Journals (Sweden)

    MANUEL CONTRERAS SEITZ

    2009-01-01

    Full Text Available Este artículo describe y analiza la constitución de corpus diacrónicos hispánicos (españoles e hispanoamericanos con el objeto de situar el marco de referencia del CorDECh (Corpus Diacrónico del Español de Chile. El trabajo presenta una intersección entre disciplinas tradicionales, como la filología y la paleografía, con especialidades lingüísticas que se han revitalizado en los últimos años, como es el caso de la lingüística del corpus, en virtud de la conformación de un corpus diacrónico del español de Chile. Además, en este texto se da cuenta de los criterios de constitución de este corpus (cronológico, de selección y transcripción documental, diatópico y de variedad de registros; asimismo, se discuten aspectos de la automatización del corpus y las implicancias y proyecciones para el análisis del mismo. Finalmente, se repasan los criterios de etiquetación del corpus, de acuerdo con los aspectos de la Text Encoding Initiative (TEI, adoptados por la RAE en el Prontuario de Marcación SGML, utilizado para el CORDE (Corpus Diacrónico del Español, junto con presentar algunos ejemplos de estos aspectos, para lo cual se utilizó el editor XML/ XSLT Cooktop 2.5.The conformation of Hispanic diachronic corpora (Spanish and Hispano-American in order to place the framework of the CorDECh (Corpus Diacrónico del Español de Chile is described and analyzed in this paper. The work shows an intersection between traditional disciplines, such as the philolology and the paleography, with linguistic disciplines that have been revitalized in the last years, such as corpus linguistics, in order to shape a Chilean Spanish diachronic corpus. In addition, the criteria of corpus formation is presented in this text (chronological, documentary selection and transcription, diatopics and register varieties; in the same way, some aspects of corpora automatization and the implications and projections for its analysis is discussed here. Finally

  4. Válvula de uretra anterior Anterior urethral valves

    Directory of Open Access Journals (Sweden)

    Silvio Tucci Jr.

    2003-02-01

    Full Text Available Objetivo: apresentar os aspectos clínicos, diagnósticos e terapêuticos de pacientes portadores de válvula da uretra anterior. Descrição: em dois neonatos, o diagnóstico presuntivo de patologia obstrutiva do trato urinário foi sugerido pela ultra-sonografia realizada no período pré-natal, confirmando-se o diagnóstico de válvula de uretra anterior pela avaliação pós-natal. Os pacientes foram submetidos a tratamento cirúrgico paliativo, com vesicostomia temporária e, posteriormente, definitivo, pela fulguração endoscópica das válvulas. Ambos evoluíram com função renal normal. Comentários: a válvula da uretra anterior é anomalia rara que deve ser considerada em meninos com quadro radiológico pré-natal sugestivo de obstrução infravesical, secundariamente à hipótese mais comum de válvula da uretra posterior. Ressaltamos a utilização da vesicostomia como derivação urinária temporária nestes casos, prevenindo potenciais complicações pela manipulação da uretra do recém-nascido.Objective: to discuss clinical signs, diagnostic tools and therapeutics of anterior urethral valves, an obstructive anomaly of the urinary system in males. Description: signs of urinary tract obstruction were identified on pre-natal ultrasound in two male fetuses and the diagnosis of anterior urethral valves was made through post-natal evaluation. As an initial treatment, vesicostomy was performed in both patients. Later, the valves were fulgurated using an endoscopic procedure. During the follow-up period both patients presented normal renal function. Comments: anterior urethral valves are a rare form of urethral anomaly that must be ruled out in boys with pre-natal ultrasound indicating infravesical obstruction. Vesicostomy used as an initial treatment rather than transurethral fulguration may prevent potential complications that can occur due to the small size of the neonatal urethra.

  5. Corpus spécialisé et ressource de spécialité

    CERN Document Server

    Jacquemin, Bernard

    2008-01-01

    "Semantic Atlas" is a mathematic and statistic model to visualise word senses according to relations between words. The model, that has been applied to proximity relations from a corpus, has shown its ability to distinguish word senses as the corpus' contributors comprehend them. We propose to use the model and a specialised corpus in order to create automatically a specialised dictionary relative to the corpus' domain. A morpho-syntactic analysis performed on the corpus makes it possible to create the dictionary from syntactic relations between lexical units. The semantic resource can be used to navigate semantically - and not only lexically - through the corpus, to create classical dictionaries or for diachronic studies of the language.

  6. Right anterior cingulate gyrus in encephalic region associated with integrating and processing Chinese words information in working memory: A functional magnetic resonance imaging study

    Institute of Scientific and Technical Information of China (English)

    Daxing Wu; Shuqiao Yao; Lirong Yan; Changlian Tan; Dewen Hu; Wai Cheong Carl Tam; Yadong Liu; Zongtan Zhou; Xiang Wang; Ding Liu

    2006-01-01

    scanner (GE Signa Twinspeed) (slice thickness 5 mm, slice gap 1.5 mm, slice parallel to line between pars geniculate and splenium in corpus callosum from corona capitis to superior part of cerebellum, totally 16 to 18 layers). ③The obtained images were pre-processed and statistically analysed with SPM 99 software. The procedure included timeslice adjusted, realigned, nomalized and smoothed. According to experimental task, data from each subject were analysed to obtain t value of each voxel. Brain activation image was got by Student's t test and statistic was presented by pseudo-color. Statistical parameter image was formed by overlapping brain activation image on three-dimensional structure image, and the threshold value was set at P< 0.05 with ten or more continous voxels (T ≥ 4.64, K ≥ 10 voxels). The brain activation images of all the subjects were calculated and overlapped into mean brain activation images. The regions with different activation density were found out. The activation voxels in regions-of-interest were checked to calculate a laterality index for each condition. The negative value indicated right hemisphere dominance.MAIN OUTCOME MEASURES: fMRI activation and laterality coefficient of Chinese numerial working task. RESULTS: Thirteen ealthy subjects participated in the result analysis. ①fMRI activation of Chinese numerial working task: The results showed that the working memory task with Chinese words not only activated left cerebral cortex including left superior frontal gyrus (BA6/10), left middle frontal gyrus (BA9), left inferior frontal gyrus (BA45/9/47), but also activated right cerebral cortex including right middle frontal gyrus (BA10/46/8), right inferior frontal lobe (BA47). Specially, peak activation was located in right anterior cingulate gyrus (BA32) with an activation volume of 879 (voxels). It indicated that superior, middle and inferior frontal gyrus, bilateral Broca regions and anterior cingutate involved in the working memory

  7. Fenestration of the anterior cerebral artery

    Energy Technology Data Exchange (ETDEWEB)

    Ito, J.; Washiyama, K.; Hong, K.C.; Ibuchi, Y.

    1981-08-01

    Three cases of angiographically demonstrated fenestration of the anterior cerebral artery are reported. Fenestration occurred at the medial half of the horizontal segment of the anterior cerebral artery in all cases. Its embryology and clinical significance are briefly discussed, and the anatomical and radiological literature on fenestration of the anterior cerebral artery is reviewed.

  8. 38 CFR 3.379 - Anterior poliomyelitis.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Anterior poliomyelitis. 3... Specific Diseases § 3.379 Anterior poliomyelitis. If the first manifestations of acute anterior poliomyelitis present themselves in a veteran within 35 days of termination of active military service, it...

  9. Epidermoid cyst in Anterior, Middle

    Directory of Open Access Journals (Sweden)

    Kankane Vivek Kumar

    2016-09-01

    Full Text Available Epidermoid cysts are benign slow growing more often extra-axial tumors that insinuate between brain structures, we present the clinical, imaging, and pathological findings in 35 years old female patients with atypical epidermoid cysts which was situated anterior, middle & posterior cranial fossa. NCCT head revealed hypodense lesion over right temporal and perisylvian region with extension in prepontine cistern with mass effect & midline shift and MRI findings revealed a non-enhancing heterogeneous signal intensity cystic lesion in right frontal & temporal region extending into prepontine cistern with restricted diffusion. Patient was detoriated in night of same day of admission, emergency Fronto-temporal craniotomy with anterior peterousectomy and subtotal resection was done. The histological examination confirms the epidermoid cyst. The timing of ectodermal tissue sequestration during fetal development may account for the occurrence of atypical epidermoid cysts.

  10. A Corpus-based Study on Keywords in The Glass Menagerie

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi-mei

    2015-01-01

    Recently, Corpus-based approach has been an important method. Based on the analysis about some Papers on corpus and corpus-based approach in literary texts, this thesis takes the work of American famous writer Tennessee Williams The Glass Menagerie as the research object. Guided by the stylistic theoretical framework put forward by Leech and Short, the study con⁃ducts text analysis with Wordsmith and Antconc3.3.1 for studying the keywords of the novel.

  11. An individual subjectivist critique of the use of corpus linguistics to inform pedagogical materials

    OpenAIRE

    Kendall Richards; Nick Pilcher

    2016-01-01

    Corpus linguistics, or the gathering together of language into a body for analysis and development of materials, is claimed to be an assured, established method (or field) that valuably informs pedagogical materials and knowledge of language (e.g. Ädel 2010; Gardner & Nesi, 2013). The fundamental validity of corpus linguistics is rarely, if ever, critiqued. In this empirical paper we critically consider the foundations of corpus linguistics as being based on an abstract objectivist view of la...

  12. A Modular and Flexible Architecture for an Integrated Corpus Query System

    OpenAIRE

    Christ, Oliver

    1994-01-01

    The paper describes the architecture of an integrated and extensible corpus query system developed at the University of Stuttgart and gives examples of some of the modules realized within this architecture. The modules form the core of a corpus workbench. Within the proposed architecture, information required for the evaluation of queries may be derived from different knowledge sources (the corpus text, databases, on-line thesauri) and by different means: either through direct lookup in a dat...

  13. A Review on Speech Corpus Development for Automatic Speech Recognition in Indian Languages

    OpenAIRE

    Cini kurian

    2015-01-01

    Corpus development gained much attention due to recent statistics based natural language processing. It has new applications in Language Technology, linguistic research, language education and information exchange. Corpus based Language research has an innovative outlook which will discard the aged linguistic theories. Speech corpus is the essential resources for building a speech recognizer. One of the main challenges faced by speech scientist is the unavailability of these resources. Very f...

  14. Morphologic Response to a New Inlet, Packery Channel, Corpus Christi, Texas

    Science.gov (United States)

    2007-01-01

    additional navigational amenity is that access to the Gulf of Mexico from the Upper Laguna Madre and Corpus Christi Bay system would be about 3 miles (5 km...Emily during construction of the jetties. The inlet connects Corpus Christi Bay and Laguna Madre to the Gulf of Mexico, the first new artificially...Packery Channel was opened by Hurricane Emily during the second year of its construction. This inlet connects Corpus Christi Bay and Upper Laguna

  15. A Research on Bilingual Dictionary Based Sentence Alignment for Chinese English Parallel Corpus

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Parallel corpus is of great importance to machine translation, and automatic sentence alignment is the first step towards its processing. This paper puts forward a bilingual dictionary based sentence alignment method for Chinese English parallel corpus, which differs from previous length based algorithm in its knowledge-rich approach. Experimental result shows that this method produces over 93% accuracy with usual English-Chinese dictionaries whose translations cover 31.88%~47.90% of the corpus.

  16. Identificação de unidades fraseológicas no vocabulário de Star Trek: abordagens corpus-driven e corpus-based

    Directory of Open Access Journals (Sweden)

    Lucas Maciel Peixoto

    2014-12-01

    Full Text Available Este artigo analisou unidades fraseológicas a partir do vocabulário existente no universo fictício de Star Trek. A base teórica usada foi a Teoria Comunicativa da Terminologia e também a Etnoterminologia, além de estudos sobre a Fraseologia. A Linguística de Corpus foi usada como base metodológica, por meio de uma abordagem corpus-driven (direcionada por corpus e outra corpus-based (baseada em corpus. Os dados examinados provieram de um corpus de estudo compilado a partir das legendas em inglês dos seriados e filmes de Star Trek, e analisado via WordSmith Tools, e também de dois corpora online de língua inglesa: o Corpus of Contemporary American English e o Google Books. Os resultados do estudo mostraram exemplos de unidades fraseológicas que são usadas dentro do universo da série, inclusive termos específicos. Além disso, também foram encontradas frases criadas pela série e ressignificadas pelos fãs, tornando-se unidades fraseológicas na língua corrente.

  17. THE CORPUS OF REGIONAL RUSSIAN-LANGUAGE NEWSPAPERS IN RUSSIA AND ABROAD

    Directory of Open Access Journals (Sweden)

    S. O. Savchuk

    2015-01-01

    Full Text Available The article describes the corpus of regional and foreign press as a new module within the RNC. Unlike newspaper corpus including only materials of the national press, the new corpus focuses on texts from regional publications. The corpus presently consists of the following subcorpora: 1 newspapers of the Grodno region (7 editions, 1.9 million tokens in total, prepared jointly with the specialists of the Grodno University, 2 Russian regional press of 2010s (13 newspapers, about 2 million tokens, 3 Russian regional press of 1990-2000 (40 newspapers, 2.6 million tokens, 4 regional releases of the national newspaper "Komsomolskaya Pravda" (6.5 million tokens. Our approach to selecting texts, the standards and software for word processing, organization of the corpus inter face are described in the article as well as the prospects of the development of corpus composition and searching instruments.The texts of the regional corpus are provided with morphological, semantic and detailed metatextual annotation. The corpus is freely available at the address http://www.ruscorpora.ru/search-regional.html. The main purpose of this corpus as we see it is to provide researchers with a tool of studying the regional variation of the Russian language.

  18. A Review on Speech Corpus Development for Automatic Speech Recognition in Indian Languages

    Directory of Open Access Journals (Sweden)

    Cini kurian

    2015-05-01

    Full Text Available Corpus development gained much attention due to recent statistics based natural language processing. It has new applications in Language Technology, linguistic research, language education and information exchange. Corpus based Language research has an innovative outlook which will discard the aged linguistic theories. Speech corpus is the essential resources for building a speech recognizer. One of the main challenges faced by speech scientist is the unavailability of these resources. Very fewer efforts have been made in Indian languages to make these resources available to public compared to English. In this paper we review the efforts made in Indian languages for developing speech corpus for automatic speech recognition.

  19. The Pedagogical Mediation of a Developmental Learner Corpus for Classroom-Based Language Instruction

    Directory of Open Access Journals (Sweden)

    Julie A. Belz

    2008-10-01

    Full Text Available Although corpora have been used in language teaching for some time, few empirical studies explore their impact on learning outcomes. We provide a microgenetic account of learners’ responses to corpus-driven instructional units for German modal particles and pronominal da-compounds. The units are based on developmental corpus data produced by native speakers during interactions with the very learners for whom the units are designed. Thus, we address the issue of authentication in corpus-driven language pedagogy. Finally, we illustrate how an ethnographically supplemented developmental learner corpus may contribute to second language acquisition research via dense documentation of micro-changes in learners’ language use over time.

  20. 33 CFR 165.809 - Security Zones; Port of Port Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi...

    Science.gov (United States)

    2010-07-01

    ... Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi Inner Harbor, Corpus Christi, TX. 165... Lavaca-Point Comfort, Point Comfort, TX and Port of Corpus Christi Inner Harbor, Corpus Christi, TX. (a) Location. The following area is designated as a security zone: all waters of the Corpus Christi...

  1. Construction of an annotated corpus to support biomedical information extraction

    Directory of Open Access Journals (Sweden)

    McNaught John

    2009-10-01

    Full Text Available Abstract Background Information Extraction (IE is a component of text mining that facilitates knowledge discovery by automatically locating instances of interesting biomedical events from huge document collections. As events are usually centred on verbs and nominalised verbs, understanding the syntactic and semantic behaviour of these words is highly important. Corpora annotated with information concerning this behaviour can constitute a valuable resource in the training of IE components and resources. Results We have defined a new scheme for annotating sentence-bound gene regulation events, centred on both verbs and nominalised verbs. For each event instance, all participants (arguments in the same sentence are identified and assigned a semantic role from a rich set of 13 roles tailored to biomedical research articles, together with a biological concept type linked to the Gene Regulation Ontology. To our knowledge, our scheme is unique within the biomedical field in terms of the range of event arguments identified. Using the scheme, we have created the Gene Regulation Event Corpus (GREC, consisting of 240 MEDLINE abstracts, in which events relating to gene regulation and expression have been annotated by biologists. A novel method of evaluating various different facets of the annotation task showed that average inter-annotator agreement rates fall within the range of 66% - 90%. Conclusion The GREC is a unique resource within the biomedical field, in that it annotates not only core relationships between entities, but also a range of other important details about these relationships, e.g., location, temporal, manner and environmental conditions. As such, it is specifically designed to support bio-specific tool and resource development. It has already been used to acquire semantic frames for inclusion within the BioLexicon (a lexical, terminological resource to aid biomedical text mining. Initial experiments have also shown that the corpus may

  2. Sentiment analysis framework organization based on twitter corpus data

    Directory of Open Access Journals (Sweden)

    Adela Beres

    2012-06-01

    Full Text Available Since its inception in 2006, Twitter has gathered millions of users. They post daily tweets about news, events or conversations. These tweets express their opinion about the topic they are discussing. Twitter is a large database of content that can be semantically exploited to extract opinions and based on these opinions to classify the users. This paper presents the organization of a sentiment analysis framework based on Twitter corpus data, including crawling tweets and opinion mining of the tweets, making it easy for its users to create portfolios of trustful Twitter accounts.

  3. English BNP identification based on corpus-trained decision tree

    Institute of Scientific and Technical Information of China (English)

    孟遥; 赵铁军; 李生; 张晓光

    2001-01-01

    Finding simple, non-recursive, base noun phrase is an important step for many natural language processing applications. This paper presents a new corpus-based approach using decision tree for that purpose. In contrast to previous methods for Base NP identification, we adopt a decision tree trained from Penn Treebank to identify Base NP. And a self-learning mechanism is further integrated into our model. Experimental results show good performances using our method. The method can also be applied to processing of any other language.

  4. Exploring the Potential of Corpus Use in Translation Training

    DEFF Research Database (Denmark)

    Laursen, Anne Lise; Pellón, Ismael Arinas

    2014-01-01

    The chapter describes the corpus analysis strategies used with the translation master’s students at the Department of Business Communication at the Faculty of Business and Social Sciences (formerly Aarhus School of Business or ASB). The short time available for the training of specialized transla...... translators only allows for teaching the students methods that they can apply systematically to several professional tasks. The chapter illustrates how the traditional translation training strategies can be combined with the use of concordancing software to cope with translations....

  5. Inner change in the Corpus Paulinum: pointers for pastoral counselling

    Directory of Open Access Journals (Sweden)

    Y. Campbell-Lane

    2007-07-01

    Full Text Available The aim of this article is to establish what perspectives exist on inner change within the “Corpus Paulinum” and how it should be applied in pastoral counselling. The Scriptural guidelines of change that will be examined for the purposes of this article, are found in the following references: Ephesians 4:22-24, Colos- sians 3:8-10, and Romans 12:1-2. The work of the Holy Spirit as “Agent of change” will also be discussed and finally some pointers on inner change and the implications for pastoral counselling will be proposed.

  6. Corpus Analysis of the Various Errors Made by the Student

    Institute of Scientific and Technical Information of China (English)

    刘启迪

    2012-01-01

      The software Wordsmith has been commonly used in corpus linguistics. In this paper, the author used the tool of Con⁃cord in Wordsmith to analyze various errors made by a student. Five passages made by the students are used. After annotating on the errors, the author uses Concord to sort out each error maker and made classification chart of the errors. All the errors are clas⁃sified into two categories:errors caused by carelessness and by language ability. After analyzing, there are mainly three kinds of er⁃rors and in the first category and five kinds of errors in the second category.

  7. iberoamérica del hábeas corpus

    Directory of Open Access Journals (Sweden)

    Jairo Enrique Herrera Pérez

    2006-01-01

    Full Text Available El hábeas corpus es actualmente el principal instrumento legal en el mundo para proteger la libertad individual contra las detenciones arbitrarias e ilegales, y así ha sido incluido en los pactos internacionales de derechos humanos y en la mayoría de las Constituciones de Europa y América. Colombia lo consagra hoy como un derecho fundamental intangible y, a la vez, una acción constitucional que tutela la libertad personal cuando alguien es privado de la libertad con violación de las garantías constitucionales o legales, o ésta se prolongue ilegalmente.

  8. Corpus analysis and automatic detection of emotion-including keywords

    Science.gov (United States)

    Yuan, Bo; He, Xiangqing; Liu, Ying

    2013-12-01

    Emotion words play a vital role in many sentiment analysis tasks. Previous research uses sentiment dictionary to detect the subjectivity or polarity of words. In this paper, we dive into Emotion-Inducing Keywords (EIK), which refers to the words in use that convey emotion. We first analyze an emotion corpus to explore the pragmatic aspects of EIK. Then we design an effective framework for automatically detecting EIK in sentences by utilizing linguistic features and context information. Our system outperforms traditional dictionary-based methods dramatically in increasing Precision, Recall and F1-score.

  9. A New Method for Ontology Matching by Using Textual Corpus

    Directory of Open Access Journals (Sweden)

    Besat Kassaie

    2014-02-01

    In this paper we propose a new method in which a text corpus is used as the source of knowledge in conjunction with a machine learning method to find matching between two ontologies .The main objective in this new method is to find similarity of two concepts based on similarity of their instances. We show how contextual knowledge hidden in domain specific documents can help us to boost the machine learning methods by providing enough features. Also we show how taking benefit from this knowledge transcends the current approaches merely detect lexical similarity by either recognizing semantic similarity of concepts.

  10. A Corpus-based Study on the Synonyms of Famous

    Institute of Scientific and Technical Information of China (English)

    JIAO Yan-wei; LUO Ying

    2016-01-01

    English is rich in synonyms. According to previous statistics, English synonyms constitute over 60%of the total English vocabulary. To have a good mastery of English lexis is to have a good mastery of English synonyms. Thus, it is significant to know how to distinguish synonyms in learning English. In traditional ways, people get information about synonyms from printed dictionaries. However, it is not enough for learners to understand the real differences of synonyms. This paper adopts a corpus-based approach to analyze the synonyms of "famous" as an example.

  11. Constitución de un corpus de semántica verbal del español: Metodología de anotación de núcleos argumentales Building a verbal semantics corpus of Spanish: Methodology for labelling phrase heads

    Directory of Open Access Journals (Sweden)

    IRENE CASTELLÓN

    2012-01-01

    Full Text Available El presente artículo detalla la metodología y el desarrollo del proyecto de desambiguación semántica de los núcleos argumentales de SenSem, un corpus equilibrado constituido por 100 oraciones para cada uno de los 250 verbos más frecuentes del español. El resultado, unido a desarrollos anteriores del proyecto, es un corpus ricamente etiquetado con información sintáctica y semántica, conectado a una base de datos que recoge la información pertinente para cada sentido verbal, por lo que el recurso resultante es adecuado para estudios empíricos centrados en el verbo. Como resultado del proceso se presenta asimismo un análisis crítico de WordNet 1.6 del español como recurso de anotación lexico-semántica de corpus y una guía de criterios de anotación, ambos de utilidad para tareas similares de etiquetado con WordNet.The SenSem Corpus and Database (Alonso, Capilla, Castellón, Fernández y Vázquez, 2007 consists of a verb-oriented balanced corpus of Spanish linked to syntactic and semantic database of predicates and sentences. The corpus consists of 100 sentences for each of the 250 more frequent verbs of Spanish. It is labelled with rich semantic and syntactic information which is structured in the database according to verb senses, thus providing an invaluable resource for verb-focused linguistic empirical research. In this paper we present the process and methodology adopted for labelling nominal argument-structure heads with WordNet sense-id's. As a by-product, both a critical assessment of Spanish WordNet 1.6 as a resource for semantic labelling and a labelling criteria guide are discussed and provided so that they might be useful in future similar research.

  12. Revisiting corpus creation and analysis tools for translation tasks

    Directory of Open Access Journals (Sweden)

    Claudio Fantinuoli

    2016-06-01

    Full Text Available Many translation scholars have proposed the use of corpora to allow professional translators to produce high quality texts which read like originals. Yet, the diffusion of this methodology has been modest, one reason being the fact that software for corpora analyses have been developed with the linguist in mind, which means that they are generally complex and cumbersome, offering many advanced features, but lacking the level of usability and the specific features that meet translators’ needs. To overcome this shortcoming, we have developed TranslatorBank, a free corpus creation and analysis tool designed for translation tasks. TranslatorBank supports the creation of specialized monolingual corpora from the web; it includes a concordancer with a query system similar to a search engine; it uses basic statistical measures to indicate the reliability of results; it accesses the original documents directly for more contextual information; it includes a statistical and linguistic terminology extraction utility to extract the relevant terminology of the domain and the typical collocations of a given term. Designed to be easy and intuitive to use, the tool may help translation students as well as professionals to increase their translation quality by adhering to the specific linguistic variety of the target text corpus.

  13. EFFE-On – Corpus Online de Escrita e Fala

    Directory of Open Access Journals (Sweden)

    Isabel Alves

    2015-11-01

    Full Text Available Neste artigo, apresentamos o funcionamento de um novo corpus de escrita e fala de crianças (Português LM nos primeiros anos da escolaridade: a EFFE-On. O seu conteúdo está disponível online para pesquisas, dirigindo-se, principalmente, a professores, linguistas e terapeutas da fala. A EFFE-On foi desenvolvida no âmbito do projeto Escreves como Falas - Falas como Escreves? no Centro de Linguística da Universidade de Lisboa (CLUL. Entre outras aplicações, o corpus permite identificar formas ortográficas não-convencionais (FN-Cs; comparar ortografias não convencionais com as suas respetivas pronúncias; auxiliar o desenvolvimento e a adequação de materiais pedagógicos e terapêuticos; examinar aspetos fonológicos, morfológicos, sintáticos, discursivos, entre outros relativos ao texto produzido pela criança.  

  14. HACIA LA CONSTITUCIÓN DE UN CORPUS DIACRÓNICO DEL ESPAÑOL DE CHILE TOWARDS CHILEAN SPANISH LANGUAGE DIACHRONIC CORPUS

    OpenAIRE

    MANUEL CONTRERAS SEITZ

    2009-01-01

    Este artículo describe y analiza la constitución de corpus diacrónicos hispánicos (españoles e hispanoamericanos) con el objeto de situar el marco de referencia del CorDECh (Corpus Diacrónico del Español de Chile). El trabajo presenta una intersección entre disciplinas tradicionales, como la filología y la paleografía, con especialidades lingüísticas que se han revitalizado en los últimos años, como es el caso de la lingüística del corpus, en virtud de la conformación de un corpus diacrónico ...

  15. TOEFL11: A Corpus of Non-Native English. Research Report. ETS RR-13-24

    Science.gov (United States)

    Blanchard, Daniel; Tetreault, Joel; Higgins, Derrick; Cahill, Aoife; Chodorow, Martin

    2013-01-01

    This report presents work on the development of a new corpus of non-native English writing. It will be useful for the task of native language identification, as well as grammatical error detection and correction, and automatic essay scoring. In this report, the corpus is described in detail.

  16. An audio-visual corpus for multimodal speech recognition in Dutch language

    NARCIS (Netherlands)

    Wojdel, J.; Wiggers, P.; Rothkrantz, L.J.M.

    2002-01-01

    This paper describes the gathering and availability of an audio-visual speech corpus for Dutch language. The corpus was prepared with the multi-modal speech recognition in mind and it is currently used in our research on lip-reading and bimodal speech recognition. It contains the prompts used also i

  17. The Effect of Corpus Assisted Language Teaching on the Learners' Proper Use of Punctuation Marks

    Science.gov (United States)

    Celik, Serkan; Elkatmis, Metin

    2013-01-01

    One of the critical contributions of the emerging technologies in computer sciences is the capability of corpus compilation and processing. Corpus resources and approaches are regarded as a potentially valuable areas both in developing instructional methods and designing pedagogical materials. This study aimed to explore the effect of exposing…

  18. A Quantitative Corpus-Based Approach to English Spatial Particles: Conceptual Symmetry and Its Pedagogical Implications

    Science.gov (United States)

    Chen, Alvin Cheng-Hsien

    2014-01-01

    The present study aims to investigate how conceptual symmetry plays a role in the use of spatial particles in English and to further examine its pedagogical implications via a corpus-based evaluation of the course books in senior high schools in Taiwan. More specifically, we adopt a quantitative corpus-based approach to investigate whether bipolar…

  19. A Corpus-Based Approach to Online Materials Development for Writing Research Articles

    Science.gov (United States)

    Chang, Ching-Fen; Kuo, Chih-Hua

    2011-01-01

    There has been increasing interest in the possible applications of corpora to both linguistic research and pedagogy. This study takes a corpus-based, genre-analytic approach to discipline-specific materials development. Combining corpus analysis with genre analysis makes it possible to develop teaching materials that are not only authentic but…

  20. A Corpus-based Analysis of Noun-verb Collocation of Knowledge

    Institute of Scientific and Technical Information of China (English)

    LIU Ting-ting

    2016-01-01

    Corpus-based analysis is adopted to study the acceptable noun-verb collocation of the word knowledge. Verbs like ac-quire, have etc. are found to be frequently collocate with knowledge, and the Chinese students’favorite patterns like learn knowledge, enlarge knowledge are not acceptable. The finding may encourage teachers to consider about the pedagogical value of corpus while teaching languages.